/Users/andrea/_magisterarbeit/korpus/clean/testkorpus/1/file10.html NN ----------------------------------------- : Empirical JJ Analysis NN of IN Internet NN Filtering VVG in IN China NP Jonathan NP Zittrain NP and CC Benjamin NP Edelman NP Berkman NP Center NP for IN Internet NP Society NP Harvard NP Law NP School NP Overview NN Methodology NN Analysis NP Summary NN Statistics NP Conclusions NNS Technical NP Appendix NN Specific NN Blocked VVN Sites NP Highlights VVZ Analysis NP by IN Google NP Keyword NP details NNS chart VVP Abstract JJ The DT authors NNS are VBP collecting VVG data NNS on IN the DT methods NNS , , scope NN , , and CC depth NN of IN selective JJ barriers NNS to TO Internet NN access NN through IN Chinese JJ networks NNS . SENT Tests NNS from IN May NP 2002 CD through IN November NP 2002 CD indicate VVP at IN least JJS four CD distinct JJ and CC independently RB operable JJ methods NNS of IN Internet NN filtering VVG , , with IN a DT documentable JJ leap NN in IN filtering VVG sophistication NN beginning NN in IN September NP 2002 CD . SENT The DT authors NNS document NN thousands NNS of IN sites NNS rendered VVN inaccessible JJ using VVG the DT most RBS common JJ and CC longstanding JJ filtering VVG practice NN . SENT These DT sites NNS were VBD found VVN through IN connections NNS to TO the DT Internet NN by IN telephone NN dial NN up IN link NN and CC through IN proxy JJ servers NNS in IN China NP . SENT Once RB so RB connected VVN , , the DT authors NNS attempted VVD to TO access VV approximately RB two CD hundred CD thousand CD web NN sites NNS . SENT The DT authors NNS tracked VVD 19 CD , , 032 CD web NN sites NNS that WDT were VBD inaccessible JJ from IN China NP on IN multiple JJ occasions NNS while IN remaining VVG accessible JJ from IN the DT United NP States NPS . SENT Such JJ sites NNS contained VVD information NN about IN news NN , , politics NNS , , health NN , , commerce NN , , and CC entertainment NN . SENT See VV highlights NNS of IN blocked VVN pages NNS . SENT The DT authors NNS conclude VVP 1 CD that IN the DT Chinese JJ government NN maintains VVZ an DT active JJ interest NN in IN preventing VVG users NNS from IN viewing VVG certain JJ web NN content NN , , both CC sexually RB explicit JJ and CC non JJ sexually RB explicit JJ . SENT 2 CD that IN it PP has VHZ managed VVN to TO configure VV overlapping VVG nationwide JJ systems NNS to TO effectively RB if IN at IN times NNS irregularly RB block VV such JJ content NN from IN users NNS who WP do VVP not RB regularly RB seek VV to TO circumvent VV such JJ blocking VVG . SENT and CC 3 CD that IN such JJ blocking VVG systems NNS are VBP becoming VVG more RBR refined VVN even RB as IN they PP are VBP likely RB more JJR labor NN and CC technology NN intensive JJ to TO maintain VV than IN cruder JJR predecessors NNS . SENT Related NP Projects NPS Real NP Time NP Testing NP of IN Internet NP Filtering VVG in IN China NP Replacement NN of IN Google NP with IN Alternative NP Search NP Systems NPS in IN China NP Documentation NN of IN Internet NN Filtering VVG in IN Saudi NP Arabia NP Web NP Sites NP Sharing VVG IP NP Addresses NNS . SENT Prevalence NN and CC Significance NN Edelman NP Documentation NN of IN Internet NN Filtering VVG Worldwide NP Other NP Resources NPS on IN Internet NP Filtering VVG in IN China NP Overview NN The DT government NN of IN the DT People's NP Republic NP of IN China NP has VHZ a DT longstanding JJ set NN of IN policies NNS restricting VVG the DT information NN to TO which WDT citizens NNS are VBP exposed VVN , , and CC that IN which WDT they PP may MD themselves PP publicly RB say VVP . SENT The DT Internet NN poses VVZ a DT new JJ challenge NN to TO such JJ censorship NN , , both CC because IN of IN the DT sheer JJ breadth NN of IN content NN typically RB available JJ , , and CC because IN sources NNS of IN content NN are VBP so RB often RB remote JJ from IN Chinese JJ jurisdiction NN , , and CC thus RB much RB more RBR difficult JJ to TO penalize VV for IN breaching VVG restrictions NNS on IN permissible JJ materials NNS . SENT There EX is VBZ some DT evidence NN that IN the DT government NN has VHZ attempted VVN to TO prevent VV the DT spread NN of IN unwanted JJ material NN by IN preventing VVG the DT spread NN of IN the DT Internet NN itself PP , , but CC a DT concomitant JJ desire NN to TO capture VV the DT economic JJ benefits NNS of IN networked VVN computing NN has VHZ led VVN to TO a DT variety NN of IN strategies NNS to TO split VV the DT difference NN . SENT For IN example NN , , the DT government NN might MD encourage VV Internet NN access NN through IN cybercafes NNS rather RB than IN in IN private JJ spaces NNS so IN that DT customers NNS surfing NN can MD be VB physically RB monitored VVN by IN others NNS in IN the DT cafe NN . SENT As IN a DT technical JJ matter NN , , anecdotal JJ reports NNS have VHP described VVN a DT shifting VVG set NN of IN barriers NNS to TO surfing VVG the DT web NN from IN Chinese JJ points NNS of IN access NN sites NNS that WDT are VBP reported VVN unavailable JJ or CC domain NN names NNS that WDT are VBP unknown JJ to TO the DT system NN or CC that DT lead NN to TO unexpected JJ destinations NNS , , individual JJ pages NNS that WDT are VBP blocked VVN , , and CC the DT use NN of IN search NN keywords NNS that IN results NNS in IN temporary JJ limits NNS to TO further JJR searches NNS . SENT As IN with IN most JJS filtering VVG regimes NNS , , whether IN implemented VVN at IN the DT client NN , , ISP NP , , or CC government NN level NN , , no DT list NN is VBZ made VVN available JJ of IN the DT sites NNS blocked VVN or CC of IN the DT methodologies NNS used VVN to TO block VV them PP . SENT Further RBR , , while IN the DT government NN connected VVN Internet NP Society NP of IN China NP not RB a DT chapter NN of IN the DT international JJ Internet NP Society NP has VHZ asked VVN Internet NN service NN providers NNS and CC content JJ creators NNS to TO sign VV a DT pledge NN including VVG self NN filtering VVG , , few JJ official NN statements NNS document VV the DT existence NN of IN government NN maintained VVN web NN filtering VVG , , much RB less JJR the DT criteria NNS employed VVN and CC thresholds NNS necessary JJ to TO elicit VV a DT block NN . SENT We PP therefore RB sought VVD to TO investigate VV the DT growing VVG set NN of IN methods NNS by IN which WDT Internet NN filtering VVG is VBZ accomplished VVN , , and CC to TO collect VV and CC distribute VV a DT list NN of IN blocked VVN sites NNS and CC pages NNS a DT list NN that WDT is VBZ large JJ in IN absolute JJ terms NNS even RB if IN small JJ relative NN to TO the DT size NN of IN the DT Internet NN and CC to TO the DT total JJ amount NN of IN blocked VVN content NN , , and CC a DT list NN that WDT is VBZ diverse JJ even RB if IN not RB perfectly RB representative JJ of IN all DT blocked VVN content NN . SENT Such PDT a DT list NN allows VVZ us PP and CC others NNS to TO begin VV to TO assess VV the DT nature NN and CC scope NN of IN filtering VVG within IN China NP , , with IN particular JJ attention NN to TO non JJ sexually RB explicit JJ web NN sites NNS rendered VVN inaccessible JJ there RB . SENT Having VHG requested VVN some DT 204 CD , , 012 CD distinct JJ web NN sites NNS , , we PP found VVD more JJR than IN 50 CD , , 000 CD to TO be VB inaccessible JJ from IN at IN least JJS one CD point NN in IN China NP on IN at IN least JJS one CD occasion NN . SENT Adopting VVG a DT more RBR conservative JJ standard NN for IN determining VVG which WDT inaccessible JJ sites NNS were VBD intentionally RB blocked VVN and CC which WDT were VBD unreachable JJ solely RB due JJ to TO temporary JJ glitches NNS , , we PP find VVP that IN 18 CD , , 931 CD sites NNS were VBD inaccessible JJ from IN at IN least JJS two CD distinct JJ proxy JJ servers NNS within IN China NP on IN at IN least JJS two CD distinct JJ days NNS . SENT We PP conclude VVP that IN China NP does VVZ indeed RB block VV a DT range NN of IN web NN content NN beyond IN that DT which WDT is VBZ sexually RB explicit JJ . SENT For IN example NN , , we PP found VVD blocking VVG of IN thousands NNS of IN sites NNS offering VVG information NN about IN news NN , , health NN , , education NN , , and CC entertainment NN , , as RB well RB as IN some DT 3 CD , , 284 CD sites NNS from IN Taiwan NP . SENT A DT look NN at IN the DT list NN beyond IN sexually RB explicit JJ content JJ yields NNS insight NN into IN the DT particular JJ areas NNS the DT Chinese JJ government NN appears VVZ to TO find VV most JJS sensitive JJ . SENT This DT report NN is VBZ intended VVN as IN a DT milepost NN , , part NN of IN an DT ongoing JJ empirical JJ investigation NN documenting VVG filtering VVG levels NNS and CC methods NNS over IN time NN . SENT As IN we PP continue VVP to TO collect VV data NNS on IN the DT evolving VVG accessibility NN of IN a DT diversified JJ basket NN of IN web NN sites NNS , , we PP will MD seek VV to TO say VV more JJR about IN overall JJ trends NNS in IN Chinese JJ web NN filtering VVG , , and CC further RBR see VV if IN such JJ trends NNS are VBP credibly RB linked VVN to TO government NN statements NNS of IN Internet NN policy NN and CC , , for IN particular JJ categories NNS of IN sensitive JJ sites NNS , , whether IN shifts NNS in IN the DT Chinese JJ government's JJ substantive JJ policy NN for IN example NN , , a DT noted VVN change NN in IN tension NN levels NNS with IN Taiwan NP are VBP reflected VVN in IN levels NNS of IN web NN filtering VVG . SENT This DT , , in IN turn NN , , can MD shed VV light NN on IN how WRB important JJ a DT priority NN web NN filtering VVG is VBZ to TO the DT government NN . SENT In IN other JJ work NN , , the DT authors NNS will MD expand VV analysis NN to TO Internet NN filtering VVG systems NNS in IN other JJ countries NNS and CC will MD generate VV additional JJ URLs NNS to TO test VV based VVN on IN queries NNS invoked VVN in IN the DT local JJ language NN . SENT Sign VV up RB to TO receive VV updates NNS . SENT The DT authors NNS are VBP also RB developing VVG a DT distributed VVN application NN for IN use NN by IN Internet NN users NNS worldwide RB in IN testing NN , , analyzing VVG , , and CC documenting VVG respective JJ Internet NN filtering VVG regimes NNS . SENT Get VV more JJR information NN and CC sign VV up RP to TO get VV involved VVN . SENT The DT authors NNS previously RB provided VVN access NN to TO a DT web NN based VVN system NN to TO test VV web NN filtering VVG in IN China NP which WDT remains VVZ available JJ . SENT Finally RB , , the DT authors NNS prepared VVD screenshots NNS documenting VVG the DT September NP 2002 CD redirection NN of IN requests NNS for IN google NN . SENT com NN to TO other JJ search NN engines NNS . SENT Testing NN Methodology NN Technical NP Notes NP on IN Chinese NP Filtering VVG Systems NP Our PP$ testing NN relied VVN on IN two CD separate JJ methods NNS of IN data NN collection NN . SENT From IN March NP 20 CD to TO May NP 6 CD , , 2002 CD , , we PP connected VVN by IN modem NN with IN an DT international JJ telephone NN call NN to TO dialup NN accounts NNS with IN several JJ Chinese JJ ISPs NNS . SENT After IN May NP 6 CD our PP$ modems NNS were VBD unable JJ to TO negotiate VV a DT handshake NN with IN modems NNS answering VVG at IN any DT Chinese NP ISPs NP , , a DT failure NN consistent JJ across IN multiple JJ phone NN lines NNS and CC locations NNS , , and CC multiple JJ ISPs NNS and CC points NNS of IN presence NN in IN China NP . SENT From IN August NP 14 CD to TO November NP 12 CD , , 2002 CD , , we PP connected JJ to TO open VV proxy JJ servers NNS in IN China NP . SENT We PP selected VVD open JJ proxies NNS with IN assistance NN from IN Ronald NP F NP . SENT Guilmette NP , , and CC we PP determined VVD their PP$ respective JJ listed JJ locations NNS for IN tabulation NN purposes NNS using VVG IP NP WHOIS NP . SENT We PP conducted VVD testing VVG of IN only RB one CD URL NN per IN web NN host NN based VVN on IN our PP$ background NN knowledge NN , , confirmed VVN in IN subsequent JJ testing NN , , that IN when WRB the DT default NN page NN of IN a DT site NN was VBD filtered VVN , , the DT entirety NN of IN that DT site NN was VBD typically RB filtered VVN . SENT Our PP$ appendix NN contains VVZ more RBR about IN this DT hypothesis NN , , its PP$ support NN , , and CC our PP$ level NN of IN confidence NN in IN it PP . SENT As IN a DT result NN , , when WRB we PP report VVP a DT site NN as IN inaccessible JJ , , it PP is VBZ typically RB the DT case NN that IN the DT entirety NN of IN that DT site NN was VBD inaccessible JJ not RB just RB the DT site's NNS default NN page NN or CC front NN page NN . SENT On IN the DT basis NN of IN our PP$ testing NN , , both CC automated JJ and CC manual JJ , , we PP have VHP reached VVN an DT increased JJ understanding NN of IN the DT design NN of IN filtering VVG systems NNS used VVN to TO restrict VV Internet NN access NN in IN China NP . SENT Our PP$ appendix NN discusses VVZ the DT details NNS of IN this DT filtering VVG , , including VVG the DT details NNS we PP have VHP inferred VVN as RB to TO the DT implementation NN of IN filtering VVG systems NNS and CC the DT prospects NNS for IN circumventing VVG them PP , , as RB well RB as IN possible JJ regional JJ variations NNS in IN filtering VVG and CC their PP$ impact NN on IN concluding VVG that IN a DT given VVN site NN is VBZ blocked VVN in IN China NP . SENT Specific JJ Sites NP Found VVD to TO be VB Blocked VVN During IN testing NN , , we PP requested VVD 204 CD , , 012 CD distinct JJ sites NNS drawn VVN from IN various JJ web NN indices NN such JJ as IN sites NNS listed VVN within IN Yahoo NN . SENT Taiwan's NP directory NN categories NNS and CC search NN results NNS such JJ as IN Google's NP top NN 100 CD results NNS for IN a DT search NN on IN China NP freedom NN . SENT Most JJS sites NNS were VBD accessible JJ from IN China NP just RB as RB from IN our PP$ standard JJ Internet NN connection NN in IN the DT United NP States NPS , , but CC we PP found VVD that IN certain JJ URLs NNS were VBD consistently RB unavailable JJ . SENT By IN attempting VVG to TO retrieve VV these DT sites NNS repeatedly RB over IN time NN , , from IN multiple JJ locations NNS within IN China NP , , we PP drew VVD inferences NNS on IN which WDT specific JJ sites NNS among IN them PP were VBD intentionally RB blocked VVN by IN Chinese JJ network NN staff NN . SENT Our PP$ subsequent JJ analysis NN considers VVZ a DT site NN to TO be VB blocked VVN if IN it PP was VBD found VVN to TO be VB inaccessible JJ by IN our PP$ testing NN system NN on IN at IN least JJS two CD distinct JJ occasions NNS from IN at IN least JJS two CD distinct JJ testing NN locations NNS in IN China NP , , and CC if IN at IN those DT times NNS it PP was VBD simultaneously RB reachable JJ from IN our PP$ main JJ testing NN location NN in IN the DT United NP States NPS . SENT Filtering VVG of IN Sexually RB Explicit JJ Content NN A DT preliminary JJ round NN of IN testing NN examined VVD 795 CD distinct JJ URLs NNS containing VVG sexually RB explicit JJ images NNS . SENT These DT URLs NP had VHD been VBN used VVN as IN the DT basis NN for IN a DT portion NN of IN one CD author's NNS expert JJ testimony NN in IN Multnomah NP County NP Public NP Library NN , , et NP al NP . SENT v NN . SENT United NP States NPS , , 201 CD F NN . SENT Supp NP . SENT 2 CD d SYM 401 CD E NN . SENT D SYM . SENT Pa NP . SENT , , 2002 CD . SENT He PP generated VVD this DT list NN by IN collecting VVG all DT 797 CD results NNS from IN Google NP in IN response NN to TO an DT October NP 2001 CD web NN search NN using VVG the DT search NN criteria NNS free JJ adult NN sex NN , , less CC two CD pages NNS removed VVN because IN they PP were VBD found VVN not RB to TO include VV sexually RB explicit JJ images NNS . SENT Of IN the DT 752 CD of IN these DT pages NNS still RB providing VVG content NN at IN the DT time NN of IN this DT testing NN , , 101 CD 13 CD . SENT 4 CD were VBD blocked VVN in IN China NP . SENT In IN contrast NN , , the DT authors NNS previously RB found VVD 695 CD 86 CD . SENT 2 CD of IN these DT same JJ sites NNS to TO be VB blocked VVN in IN Saudi NP Arabia NP , , and CC one CD author NN previously RB found VVD that IN leading VVG commercial JJ filtering VVG applications NNS blocked VVD 70 CD to TO 90 CD of IN these DT sites NNS . SENT Filtering VVG of IN Other JJ Content NN Our PP$ main JJ testing NN examined VVD 203 CD , , 217 CD web NN sites NNS drawn VVN from IN categories NNS other JJ than IN sexually RB explicit JJ content NN . SENT We PP seeded VVD this DT list NN of IN sites NNS from IN multiple JJ sources NNS . SENT For IN example NN , , we PP extracted VVD from IN Yahoo NN all DT web NN sites NNS in IN certain JJ categories NNS including VVG those DT specifically RB about IN education NN , , entertainment NN , , news NN , , major JJ world NN governments NNS , , and CC politics NNS as RB well RB as IN all DT sites NNS in IN the DT non JJ English JJ regional JJ versions NNS of IN Yahoo NN that IN specifically RB concern NN China NP and CC Taiwan NP . SENT We PP conducted VVD searches NNS on IN terms NNS likely JJ to TO yield VV sensitive JJ results NNS and CC thus RB candidates NNS for IN blocking VVG , , both CC in IN English NP and CC in IN Chinese JJ , , using VVG the DT Google NP search NN engine NN , , and CC placed VVD the DT top JJ results NNS into IN our PP$ list NN of IN URLs NP to TO test VV . SENT We PP tracked VVD approximately RB 5 CD , , 000 CD additional JJ sites NNS submitted VVN to TO our PP$ Real NP Time NP Testing NP System NP through IN September NP 2002 CD , , and CC we PP received VVD email NP suggestions NNS of IN further JJR sites NNS to TO test VV . SENT The DT result NN of IN these DT data NN sources NNS was VBD a DT list NN of IN 203 CD , , 217 CD distinct JJ host NN names NNS . SENT Using VVG the DT definition NN of IN blocked VVN specified JJ above IN , , we PP found VVD that IN a DT total NN of IN 18 CD , , 931 CD of IN these DT sites NNS 9 CD . SENT 3 CD were VBD blocked VVN in IN China NP . SENT Given VVN the DT large JJ number NN of IN sites NNS blocked VVN , , we PP have VHP organized VVN our PP$ listing NN of IN specific JJ blocked VVN pages NNS into IN highlights NNS some DT blocked VVN pages NNS that WDT are VBP well RB known VVN or CC otherwise RB of IN possible JJ interest NN followed VVN by IN the DT full JJ list NN . SENT Where WRB available JJ , , each DT page's NN listing NN includes VVZ its PP$ HTML NP title NN , , its PP$ META NP keywords NNS and CC description NN , , and CC its PP$ Yahoo NN Directory NN and CC Google NP Directory NN classifications NNS . SENT These DT details NNS are VBP as RB retrieved VVN in IN November NP 2002 CD . SENT Specific JJ web NN sites NNS blocked VVN in IN China NP Highlights VVZ of IN blocked VVN sites NNS sites NNS that WDT are VBP well RB known VVN or CC otherwise RB of IN particular JJ interest NN Complete JJ list NN of IN 18 CD , , 931 CD blocked VVN sites NNS , , sorted VVN alphabetically RB by IN URL NP A NP B NP C NP D NP E NP F NP G NP H NP I NP J NP K NP L NP M NP N NP O NP P NN Q NP R NP S NP T NN U NP V NN W NP X NP Y NP Z NP numbers NNS Content NN Not RB Filtered VVN Within IN the DT context NN of IN the DT large JJ number NN of IN sites NNS found VVN to TO be VB restricted VVN in IN China NP , , many JJ other JJ sites NNS are VBP not RB blocked VVN in IN China NP , , whether IN because IN they PP have VHP yet RB to TO be VB passed VVN upon RP by IN the DT authorities NNS that WDT determine VVP blocks NNS or CC because IN they PP have VHP been VBN affirmatively RB found VVN to TO be VB non JJ sensitive JJ . SENT Sites NNS not RB blocked VVN may MD assist VV in IN drawing VVG inferences NNS about IN what WP content NN among IN the DT blocked VVN sites NNS is VBZ responsible JJ for IN the DT differential JJ treatment NN . SENT For IN example NN , , filtering VVG of IN the DT United NP States NPS Federal NP Courts NPS uscourts NNS . SENT gov NP and CC all DT subdomains NNS might MD indicate VV a DT desire NN to TO prevent VV access NN to TO information NN about IN the DT American JJ judicial JJ system NN , , its PP$ processes NNS , , and CC its PP$ rulings NNS but CC Findlaw NP , , LexisNexis NP , , and CC Westlaw NP all RB remain VVP accessible JJ . SENT Similarly RB , , blocking VVG of IN well RB known VVN sexually RB explicit JJ sites NNS such JJ as IN Playboy NN and CC Penthouse NN suggests VVZ a DT purposeful JJ decision NN to TO restrict VV sexually RB explicit JJ material NN yet CC the DT well RB known VVN sites NNS of IN Hustler NN Magazine NP and CC whitehouse NP . SENT com NN were VBD consistently RB accessible JJ in IN the DT authors NNS testing NN . SENT Additional JJ hosts NNS tested VVN but CC not RB found VVD to TO be VB inaccessible JJ . SENT ZIP VV file VV Analysis NP Summary NN Statistics NNS Among IN the DT specific JJ blocked VVN pages NNS are VBP the DT following VVG categories NNS of IN content NN . SENT Dissident JJ democracy NN sites NNS . SENT Blocked VVN sites NNS includes VVZ sites NNS about IN democracy NN and CC human JJ rights NNS generally RB and CC sites NNS specific JJ to TO China NP . SENT Of IN the DT top JJ 100 CD sites NNS returned VVN by IN Google NP in IN response NN to TO a DT search NN for IN democracy NN china NN , , 40 CD were VBD found VVN to TO be VB blocked VVN , , while IN 37 CD dissident JJ china NN sites NNS were VBD blocked VVN , , 32 CD were VBD blocked VVN for IN freedom NN china NN , , and CC 30 CD for IN justice NN china NN . SENT Specific JJ blocked VVN sites NNS included VVD Amnesty NN International NP , , Human NP Rights NPS Watch NN , , the DT Hong NP Kong NP Voice NP of IN Democracy NP , , the DT Direct NP Democracy NP Center NP , , and CC dozens NNS of IN Falun NP Gong NP and CC Falun NP Dafa NP sites NNS . SENT Health NN . SENT Blocked VVN sites NNS included VVD sites NNS about IN health NN generally RB and CC about RB health NN in IN China NP specifically RB . SENT Of IN the DT top JJ 100 CD Google NP results NNS for IN hunger NN china NN , , 24 CD were VBD blocked VVN . SENT for IN famine NN china NN 23 CD . SENT for IN AIDS NP china NN 21 CD . SENT for IN sex NN china NN 19 CD . SENT for IN disease NN china NN 14 CD . SENT Specific JJ blocked VVN sites NNS included VVD the DT AIDS NP Healthcare NP Foundation NP , , the DT Internet NP Mental JJ Health NP reference NN , , and CC the DT Health NP in IN China NP research NN project NN . SENT We PP found VVD blocking VVG of IN a DT total NN of IN 139 CD sites NNS listed VVN in IN Yahoo's NP Health NP directory NN categories NNS and CC subcategories NNS . SENT Education NN . SENT Blocked VVN sites NNS included VVD a DT number NN of IN well RB known VVN institutions NNS of IN higher JJR education NN , , including VVG the DT primary JJ web NN servers NNS operated VVN by IN Caltech NP , , Columbia NP , , MIT NP , , and CC the DT University NP of IN Virginia NP . SENT Blocked VVN non JJ university NN sites NNS included VVD the DT Learning NP Channel NP , , the DT Islamic JJ Virtual JJ School NP , , the DT Music NP Academy NP of IN Zheng NP , , and CC the DT web NN sites NNS of IN dozens NNS of IN public JJ and CC private JJ primary JJ and CC secondary JJ schools NNS . SENT We PP further RBR found VVD evidence NN of IN blocking VVG of IN 696 CD sites NNS listed VVN in IN Yahoo's NP Education NP directory NN categories NNS and CC subcategories NNS . SENT News NN . SENT The DT BBC NP News NP was VBD consistently RB unreachable JJ , , while IN CNN NP , , Time NP Magazine NP , , PBS NP , , the DT Miami NP Herald NP , , and CC the DT Philadelphia NP Inquirer NN were VBD also RB often RB unavailable JJ . SENT Of IN Google's NP top NN 100 CD results NNS for IN news NN , , 42 CD were VBD blocked VVN . SENT We PP further RBR found VVD evidence NN of IN blocking VVG of IN 923 CD sites NNS listed VVN in IN Yahoo's NP News NP and CC Media NP directory NN categories NNS and CC subcategories NNS . SENT Nonetheless RB , , some DT news NN sites NNS that WDT were VBD previously RB blocked VVN became VVD accessible JJ during IN the DT course NN of IN our PP$ testing NN . SENT for IN example NN , , Reuters NP was VBD blocked VVN through IN April NP 29 CD , , but CC was VBD subsequently RB accessible JJ , , while IN the DT Washington NP Post NP was VBD blocked VVN through IN May NP 6 CD and CC was VBD subsequently RB accessible JJ . SENT This DT reduction NN in IN blocking VVG of IN entire JJ news NN sites NNS may MD reflect VV that DT certain JJ new JJ filtering VVG technologies NNS discussed VVN in IN greater JJR detail NN in IN the DT appendix NN allow VV blocking VVG only RB of IN the DT particular JJ sections NNS and CC articles NNS that WDT are VBP particularly RB controversial JJ in IN China NP . SENT As IN a DT result NN , , our PP$ results NNS should MD not RB be VB taken VVN to TO suggest VV that IN every DT Washington NP Post NP article NN is VBZ now RB accessible JJ in IN China NP . SENT Government NN sites NNS . SENT Blocked VVN sites NNS included VVD a DT variety NN of IN sites NNS operated VVN by IN governments NNS in IN Asia NP and CC beyond IN . SENT As RB discussed VVN below RB , , government NN sites NNS of IN Taiwan NP and CC Tibet NP were VBD targeted VVN specifically RB . SENT Also RB blocked VVN was VBD the DT entirety NN of IN uscourts NNS . SENT gov NP , , including VVG the DT many JJ federal JJ district NN and CC appellate JJ courts NNS in IN the DT United NP States NPS , , as RB well RB as IN the DT United NP Kingdom's NP Court NP Service NP and CC Israel's NP Judicial NP Authority NP . SENT The DT communication NN sites NNS of IN various JJ governments NNS were VBD blocked VVN , , including VVG the DT United NP States NPS Voice NP of IN America NP , , as RB well RB as IN travel NN sites NNS from IN Australia NP , , Israel NP , , Korea NP , , Switzerland NP , , and CC Wales NP . SENT Government NN military JJ department NN sites NNS were VBD also RB blocked VVN , , including VVG the DT US NP Department NP of IN Defense NP , , though IN others NNS remained VVD reachable JJ the DT CIA NP . SENT A DT variety NN of IN additional JJ government NN sites NNS were VBD blocked VVN , , without IN manifest JJ pattern NN , , both CC in IN the DT United NP States NPS and CC beyond IN . SENT examples NNS include VVP the DT site NN of IN Seattle's NP King NP County NP , , the DT main JJ Australian JJ Federal NP Government NP index NN site NN , , the DT Philippines NP Bureau NP of IN Customs NP , , the DT British JJ Insolvency NN Service NP , , the DT Office NN of IN the DT Governor NP of IN Makkah NP in IN Saudi NP Arabia NP , , and CC the DT Legislative JJ Assembly NN of IN British NP Columbia NP . SENT Blocked VVN sites NNS included VVD 516 CD sites NNS in IN Yahoo's NP categories NNS and CC subcategories NNS pertaining VVG to TO governments NNS . SENT Taiwanese JJ and CC Tibetan JJ sites NNS generally RB . SENT Blocked VVN sites NNS included VVD business NN sites NNS like IN the DT A NP D NP Company NP of IN Taiwan NP , , non JJ commercial JJ sites NNS the DT Taiwan NP Health NP Clinic NP and CC a DT total NN of IN 709 CD . SENT edu NN . SENT tw JJ sites NNS , , as RB well RB as IN the DT Voice NP of IN Tibet NP , , and CC government NN sites NNS the DT Office NN of IN the DT President NP of IN Taiwan NP and CC the DT Taiwanese JJ Parliamentary JJ Library NN among IN 936 CD other JJ Taiwanese JJ government NN sites NNS , , and CC the DT Official NP Website NP of IN the DT Tibetan JJ Government NN in IN Exile NN . SENT More JJR than IN 60 CD of IN Google's NP top NN 100 CD Tibet NP sites NNS were VBD found VVN to TO be VB blocked VVN , , and CC more JJR than IN 47 CD of IN the DT top JJ Taiwan NP sites NNS were VBD blocked VVN . SENT Taiwanese JJ content NN was VBD also RB blocked VVN disproportionately RB , , relative JJ to TO its PP$ representation NN in IN our PP$ testing NN sample NN . SENT fully RB 3 CD , , 284 CD . SENT TW NP sites NNS 13 CD . SENT 4 CD of IN . SENT TW NP sites NNS tested VVD were VBD blocked VVN , , while IN our PP$ overall JJ block NN rate NN was VBD approximately RB 9 CD . SENT 3 LS . SENT Of IN course NN , , comparisons NNS of IN block NN rates NNS must MD be VB performed VVN with IN care NN given VVN the DT subjective JJ formation NN of IN the DT list NN of IN sites NNS tested VVN . SENT For IN lack NN of IN a DT domain NN name NN specifically RB associated VVN with IN Tibetan JJ sites NNS , , it PP is VBZ more RBR difficult JJ to TO perform VV such PDT a DT comparison NN on IN the DT block NN rate NN of IN Tibetan JJ content NN . SENT Entertainment NP . SENT Blocked VVN sites NNS included VVD the DT movie NN Deep NP Impact NP , , the DT Canadian NP Music NP Centre NP , , the DT Taiwanese JJ site NN of IN MTV NP mtv NP . SENT com NN . SENT tw JJ and CC multiple JJ sites NNS providing VVG off RP color NN jokes NNS . SENT We PP also RB found VVD blocking VVG of IN a DT total NN of IN 451 CD sites NNS in IN Yahoo's NP categories NNS and CC subcategories NNS pertaining VVG to TO Entertainment NP . SENT Religion NN . SENT Blocked VVN sites NNS included VVD the DT Asian JJ American NP Baptist NP Church NP , , the DT Atheist NN Network NP , , the DT Catholic NP Civil NP Rights NPS League NP , , Feng NP Shui NP at IN Geomancy NN . SENT net JJ , , the DT Canberra NP Islamic NP Centre NP , , the DT Jewish JJ Federation NP of IN Winnipeg NP , , and CC the DT Denver NP Zen NP Center NP . SENT We PP found VVD blocking VVG of IN a DT total NN of IN 1 CD , , 763 CD sites NNS in IN Yahoo's NP categories NNS and CC subcategories NNS pertaining VVG to TO religion NN . SENT The DT authors NNS obtained VVD selected VVN sites NNS from IN Google NP searches NNS on IN designated VVN keywords NNS . SENT The DT graph NN and CC tables NNS linked VVD below RB report VV the DT proportion NN of IN sites NNS found VVN to TO be VB blocked VVN in IN response NN to TO searches NNS on IN specific JJ keywords NNS . SENT Blocking VVG of IN search NN results NNS by IN Google NP Keyword NP Blocking VVG of IN search NN results NNS by IN Google NP Keyword NP with IN blocked VVN site NN details NNS Blocking VVG of IN search NN results NNS by IN Google NP Keyword NP chart NN Blocking VVG was VBD found VVN to TO vary VV across IN locations NNS in IN China NP . SENT However RB , , the DT authors NNS lack VVP sufficient JJ data NNS to TO draw VV conclusions NNS about IN systematic JJ variations NNS in IN blocking VVG across IN geographic JJ locations NNS . SENT current JJ data NNS is VBZ consistent JJ both CC with IN intentional JJ variations NNS in IN blocking VVG and CC with IN delays NNS in IN updating VVG block NN lists NNS in IN certain JJ regions NNS . SENT The DT authors NNS previously RB made VVD available JJ to TO the DT public NN a DT real JJ time NN testing NN site NN whereby WRB interested JJ Internet NN users NNS could MD submit VV URLs NNS for IN immediate JJ testing NN through IN Chinese JJ filtering VVG systems NNS . SENT Between IN August NP 28 CD and CC November NP 21 CD , , 2002 CD , , this DT system NN received VVD a DT total NN of IN 100 CD , , 563 CD requests NNS to TO test VV 13 CD , , 569 CD distinct JJ URLs NNS on IN 12 CD , , 335 CD distinct JJ host NN names NNS . SENT More JJR than IN 5 CD , , 000 CD of IN these DT hosts NNS had VHD not RB previously RB been VBN selected VVN by IN the DT authors NNS for IN testing NN . SENT Having VHG previously RB examined VVN Internet NN filtering VVG in IN Saudi NP Arabia NP , , the DT authors NNS tested VVN through IN Chinese JJ filtering VVG systems NNS all DT sites NNS previously RB tested VVN in IN Saudi NP Arabia NP . SENT The DT authors NNS had VHD previously RB tested VVN 49 CD , , 586 CD distinct JJ hosts NNS through IN filtering VVG systems NNS in IN Saudi NP Arabia NP and CC had VHD found VVN that DT country NN to TO restrict VV access NN to TO at IN least JJS certain JJ content NN on IN a DT total NN of IN 582 CD of IN these DT hosts NNS 1 CD . SENT 2 CD of IN sampled VVN hosts NNS . SENT China NP also RB filtered VVN 101 CD of IN these DT hosts NNS 0 CD . SENT 2 CD , , while IN China NP filtered VVN 5 CD , , 903 CD additional JJ hosts NNS 11 CD . SENT 9 CD of IN the DT sample NN not RB filtered VVN in IN Saudi NP Arabia NP . SENT The DT chart NN below RB depicts VVZ the DT extent NN of IN overlap VV between IN filtering VVG in IN China NP and CC in IN Saudi NP Arabia NP . SENT Note NN that IN the DT representation NN of IN hosts NNS not RB blocked VVN is VBZ not RB to TO scale NN , , relative JJ to TO the DT rest NN of IN the DT chart NN . SENT Conclusions NNS From IN our PP$ data NNS , , it PP appears VVZ that IN the DT set NN of IN sites NNS blocked VVN in IN China NP is VBZ by IN no DT means VVZ static JJ . SENT whoever WP maintains VVZ the DT lists NNS is VBZ actively RB updating VVG them PP , , and CC certain JJ general JJ interest NN high JJ profile NN sites NNS whose WP$ content JJ changes NNS frequently RB appear VVP to TO be VB blocked VVN and CC unblocked JJ as IN those DT changes NNS are VBP evaluated VVN . SENT This DT is VBZ particularly RB noticeable JJ with IN news NN sites NNS such JJ as IN CNN NP and CC Slashdot NP . SENT Some DT new JJ sites NNS with IN sensitive JJ content NN do VVP not RB appear VV to TO take VV long RB to TO be VB blocked VVN . SENT However RB , , even RB some DT longstanding JJ sites NNS of IN apparent JJ sensitivity NN remain VVP unblocked JJ . SENT This DT is VBZ most RBS easily RB noticed VVN in IN our PP$ data NNS with IN respect NN to TO sexually RB explicit JJ sites NNS we PP found VVD blocking VVG of IN only RB 13 CD . SENT 4 CD of IN our PP$ sample NN of IN well RB known VVN sexually RB explicit JJ sites NNS but CC is VBZ also RB anecdotally RB apparent JJ from IN our PP$ data NNS , , as RB one CD notes NNS blocking VVG of IN some DT US NP intelligence NN sites NNS but CC not RB others NNS , , etc FW . SENT Further JJR data NNS collection NN will MD be VB geared VVN at IN determining VVG the DT extent NN to TO which WDT the DT basket NN of IN sites NNS blocked VVN reflects VVZ shifting VVG substantive JJ government NN policies NNS whether IN , , for IN example NN , , a DT sea NN change NN in IN relations NNS with IN Taiwan NP , , whether IN positive JJ or CC negative JJ , , is VBZ reflected VVN in IN blocking VVG , , and CC if IN so RB , , how WRB quickly RB . SENT China's NP Internet NP filtering VVG efforts NNS remain VVP opaque JJ , , and CC in IN the DT absence NN of IN government NN cooperation NN or CC admission NN of IN filtering VVG methods NNS , , data NNS probing VVG of IN the DT sort NN used VVN in IN our PP$ study NN remains VVZ a DT useful JJ tool NN in IN determining VVG the DT scope NN of IN filtering VVG . SENT The DT authors NNS have VHP previously RB studied VVN filtering VVG in IN Saudi NP Arabia NP and CC in IN American JJ public JJ libraries NNS . SENT in IN these DT locations NNS , , blockage NN of IN a DT web NN page NN leads VVZ to TO an DT error NN message NN clearly RB explaining VVG that IN the DT requested VVN page NN is VBZ unavailable JJ due RB to TO intentional JJ blockage NN . SENT In IN contrast NN , , China's NP systems NNS make VVP it PP difficult JJ for IN a DT user NN to TO distinguish VV between IN an DT intentional JJ block NN and CC a DT temporary JJ network NN or CC server NN glitch NN . SENT This DT may MD be VB intentional JJ or CC may MD reflect VV technical JJ happenstance NN that IN this DT implementation NN was VBD easier JJR or CC cheaper JJR , , given VVN the DT size NN and CC design NN of IN China's NP network NN infrastructure NN . SENT But CC some DT newer JJR forms NNS of IN Chinese JJ filtering VVG namely RB , , redirection NN of IN a DT request NN for IN a DT sensitive JJ web NN site NN to TO another DT web NN site NN can MD be VB either RB more JJR or CC less RBR obvious JJ to TO the DT user NN than IN an DT apparent JJ network NN glitch NN , , depending VVG on IN whether IN the DT substitution NN is VBZ noticed VVN . SENT The DT primary JJ and CC most RBS longstanding JJ means NNS of IN blocking VVG is VBZ at IN the DT router NN level NN , , and CC on IN the DT basis NN of IN IP NP address VV the DT crudity NN of IN which WDT means VVZ that IN those DT implementing VVG filtering VVG must NN choose VVP between IN blocking VVG an DT entire JJ site NN on IN the DT basis NN of IN a DT small JJ portion NN of IN its PP$ content NN , , or CC tolerating VVG such JJ content NN . SENT This DT would MD explain VV why WRB , , for IN example NN , , the DT www NP . SENT mit NP . SENT edu NN server NN is VBZ sometimes RB wholly RB inaccessible JJ even RB though IN Chinese JJ officials NNS likely RB have VHP no DT objection NN to TO most JJS content NN on IN that DT server NN . SENT To TO the DT extent NN that IN the DT entirety NN of IN that DT server NN is VBZ nonetheless RB inaccessible JJ , , China's JJ filtering VVG system NN is VBZ properly RB considered VVN to TO be VB overblocking JJ , , and CC we PP believe VVP our PP$ data NN indicates VVZ extensive JJ overblocking NN of IN this DT form NN . SENT This DT may MD account VV for IN the DT rise NN of IN still RB rare JJ forms NNS of IN blocking VVG that IN allow VV more RBR refined JJ content NN filtering VVG such JJ as IN blocking VVG by IN keywords NNS or CC phrases NNS in IN any DT particular JJ HTML NP page NN requested VVD by IN a DT user NN , , whether IN or CC not RB the DT site NN hosting VVG the DT page NN is VBZ present JJ on IN an DT ex JJ ante NN block NN list NN . SENT Such JJ blocking VVG is VBZ likely RB far RB more JJR technology NN intensive JJ , , in IN principle NN even RB slowing VVG overall JJ network NN response NN time NN as IN packets NNS are VBP analyzed VVN by IN sniffers NNS and CC the DT results NNS passed VVN to TO filters NNS . SENT Aside RB from IN allowing VVG more RBR refined JJ content NN filtering VVG , , such JJ newer JJR forms NNS of IN blocking VVG appear VVP to TO be VB linked VVN to TO disabling VVG Internet NN access NN for IN an DT arbitrary JJ amount NN of IN time NN for IN a DT user NN who WP requested VVD a DT page NN with IN forbidden VVN content NN enabling VVG a DT penalty NN for IN attempting VVG access NN to TO sensitive JJ material NN beyond IN simply RB denying VVG the DT very JJ material NN requested VVD . SENT Other JJ nascent JJ but CC growing VVG forms NNS of IN filtering VVG appear VVP to TO be VB targeted VVN to TO limit VV the DT information NN that WDT can MD be VB gleaned VVN from IN search NN engines NNS enabling VVG the DT automated JJ blocking VVG of IN search NN results NNS that WDT may MD not RB yet RB have VHP been VBN filtered VVN through IN human JJ placement NN on IN a DT forbidden VVN list NN . SENT The DT Chinese JJ government NN and CC associated VVN network NN authorities NNS are VBP clearly RB continuing VVG to TO experiment NN with IN different JJ forms NNS of IN blocking VVG , , indicating VVG that IN unlike IN Saudi NP Arabia NP , , which WDT appears VVZ to TO have VH a DT single JJ , , declared VVD method NN of IN blocking VVG and CC a DT much RB more RBR constant JJ and CC apparently RB smaller JJR list NN of IN non JJ sexually RB explicit JJ blocked VVN sites NNS Chinese JJ network NN filtering VVG is VBZ an DT important JJ instrument NN of IN state NN Internet NN policy NN , , and CC one NN to TO which WDT significant JJ technical JJ and CC human JJ resources NNS continue VVP to TO be VB devoted VVN . SENT Additional JJ details NNS on IN data NN collection NN and CC interpretation NN are VBP available JJ in IN the DT technical JJ appendix NN . SENT The DT authors NNS have VHP also RB indexed VVN related JJ work NN by IN others NNS . SENT The DT authors NNS are VBP grateful JJ to TO Ronald NP F NP . SENT Guilmette NP for IN assistance NN with IN locating VVG proxy JJ servers NNS in IN China NP , , to TO Joshua NP Rosenzweig NP of IN the DT Dui NP Hua NP Foundation NP for IN assistance NN in IN locating VVG routing NN glitches NNS , , and CC to TO Nongji NP Zhang NP of IN the DT Harvard NP Law NP School NP Library NN for IN assistance NN with IN Chinese JJ translations NNS . SENT A DT version NN of IN this DT document NN was VBD included VVN in IN the DT March NP April NP 2003 CD edition NN of IN IEEE NP Internet NP Computing NP . SENT Jack NP N NP . SENT and CC Lillian NP R NP . SENT Berkman NP Assistant NP Professor NP of IN Entrepreneurial JJ Legal NP Studies NPS , , Harvard NP Law NP School NP . SENT J NP . SENT D SYM . SENT Candidate NN , , Harvard NP Law NP School NP , , 2005 CD . SENT Support NN for IN this DT project NN was VBD provided VVN by IN the DT Berkman NP Center NP for IN Internet NP Society NP at IN Harvard NP Law NP School NP . SENT Last RB Updated VVN . SENT March NP 20 CD , , 2003 CD Sign NN up RP for IN notification NN of IN major JJ updates NNS and CC related JJ work NN . SENT honey NN h NN 2 CD odev NN . SENT law NN . SENT harvard NP . SENT edu NP