Looks like the active part of the opt-out involves making the user load the following URLs (they use the script tag, but 1x1 images could do): * http://http300

Looks like the active part of the opt-out involves making the user load the following URLs (they use the script tag, but 1x1 images could do): * http://http300.edge.ru4.com/smartserve/optout http://http300.edge.ru4.com/smartserve/optout * http://www.247realmedia.com/EN-US/opt-out.html http://www.247realmedia.com/EN-US/opt-out.html * http://scripts.adcentriconline.com/optout.php http://scripts.adcentriconline.com/optout.php * http://oo.afy11.net/Default.aspx http://oo.afy11.net/Default.aspx * http://nspmotion.com/setoptout.aspx http://nspmotion.com/setoptout.aspx * http://ads.heias.de/x/opt_out.php?opt_out=true http://ads.heias.de/x/opt_out.php?opt_out=true * http://www.abmr.net/set_optout?nocache=0.1764119 http://www.abmr.net/set_optout?nocache=0.1764119 * http://pbid.pro-market.net/engine?optout=$nai_optout$nocache=0.5716212 http://pbid.pro-market.net/engine?optout=$nai_optout$nocache... * http://www.atdmt.com/CookieUpdate.aspx?option=Outredir=CookieActions.aspx http://www.atdmt.com/CookieUpdate.aspx?option=Outredir=Cooki... * http://optout.revsci.net/optout.aspx?a=1&p=http://www.networkadvertising.org&nocache=0.2084559 http://optout.revsci.net/optout.aspx?a=1&p=http://www.ne... * http://www.bizo.com/businessProfessionals/opt_out?confirm=true http://www.bizo.com/businessProfessionals/opt_out?confirm=tr... * http://tags.bluekai.com/naioptout?nocache=0.4754892 http://tags.bluekai.com/naioptout?nocache=0.4754892 http://s0b.bluestreak.com/ix.e?sc&t=0 http://s0b.bluestreak.com/ix.e?sc&t=0 * http://www.brightroll.com/privacy/opt-out/ http://www.brightroll.com/privacy/opt-out/ * http://www.btbuckets.com/site/optout_submit http://www.btbuckets.com/site/optout_submit * http://api.choicestream.com/instr/ad/opt-out http://api.choicestream.com/instr/ad/opt-out * http://optout.collective-media.net/optout?nocache=0.3432681 http://optout.collective-media.net/optout?nocache=0.3432681 * http://data.cmcore.com/privacy/privacy_handler.php?dest=http://data.cmcore.com/privacy/getCoreStatus.php&act=opt_out http://data.cmcore.com/privacy/privacy_handler.php?dest=http... * http://load.exelator.com/load/OptOut.php?service=outNAI&nocache=0.5863306 http://load.exelator.com/load/OptOut.php?service=outNAI&... * http://as.serving-sys.com/OptOut/SetOptOut.asp?OptOut=TRUE http://as.serving-sys.com/OptOut/SetOptOut.asp?OptOut=TRUE * http://www.facilitatedigital.com/cookie_opt_out.asp http://www.facilitatedigital.com/cookie_opt_out.asp * http://fetchback.com/serve/fb/optout?nocache=0.3366319 http://fetchback.com/serve/fb/optout?nocache=0.3366319 * http://p.opt.fimserve.com/nai_opt.jsp?nocache=9.096128E-02 http://p.opt.fimserve.com/nai_opt.jsp?nocache=9.096128E-02 * http://cue.v.fwmrm.net/ad/optout http://cue.v.fwmrm.net/ad/optout * http://optout.doubleclick.net/cgi-bin/dclk/optoutnai.pl http://optout.doubleclick.net/cgi-bin/dclk/optoutnai.pl * http://a1.interclick.com/optOut.aspx?optOut=true&success=http%3A//w2.interclick.com/opt-out-success.aspx&fail=http%3A//w2.interclick.com/opt-out-failure.aspx http://a1.interclick.com/optOut.aspx?optOut=true&success... * http://www.crwdcntrl.net/optout http://www.crwdcntrl.net/optout * http://media6degrees.com/optout_.php http://media6degrees.com/optout_.php * http://action.mathtag.com/mm/OPTO/opt-out/OPT?oo=1 http://action.mathtag.com/mm/OPTO/opt-out/OPT?oo=1 * http://mmismm.com/mm_oo.php?opt_out=&nocache=0.7812027 http://mmismm.com/mm_oo.php?opt_out=&nocache=0.7812027 * http://www.nexac.com/nai_optout.php?nocache=2.282816E-02 http://www.nexac.com/nai_optout.php?nocache=2.282816E-02 * http://www.nextag.com/serv/main/buyer/help/AdTargetingOptOut.jsp http://www.nextag.com/serv/main/buyer/help/AdTargetingOptOut... * http://eu.nuggad.net/block http://eu.nuggad.net/block * http://www.openx.org/privacy?action=opt-out http://www.openx.org/privacy?action=opt-out * http://adserver.adtech.de/setoptoutcookie/?page=http://glb.adtechus.com/setoptoutcookie/?page=http://adserverwc.adtechus.com/setoptoutcookie/?page=http://adserverec.adtechus.com/setoptoutcookie/?page=http://ad.us-ec.adtechus.com/setoptoutcookie/?page=http http://adserver.adtech.de/setoptoutcookie/?page=http://glb.a... * http://www.precisionclick.com/optout_set.asp http://www.precisionclick.com/optout_set.asp * http://ch.questionmarket.com/safecount/nai_optout.php?nocache=0.2979517 http://ch.questionmarket.com/safecount/nai_optout.php?nocach... * http://notrack.adviva.net/CookieCheck.php?optThis=1 http://notrack.adviva.net/CookieCheck.php?optThis=1 * http://ad.trafficmp.com/a/optout?s=naiz http://ad.trafficmp.com/a/optout?s=naiz * http://www.exponential.com/who-we-are/cookie-thankyou.jsp http://www.exponential.com/who-we-are/cookie-thankyou.jsp * http://r.turn.com/r/optout?type=setOptOut&nocache=0.9414226 http://r.turn.com/r/optout?type=setOptOut&nocache=0.9414... * http://www.mediaplex.com/optout_pure.php?nocache=0.9477198 http://www.mediaplex.com/optout_pure.php?nocache=0.9477198 * http://info.yahoo.com/nai/nai-status.html?optout http://info.yahoo.com/nai/nai-status.html?optout * http://ads.undertone.com/fc.php?script=optOutUser:optOutUser&action=opt-out&nocache=0.8926813 http://ads.undertone.com/fc.php?script=optOutUser:optOutUser... * http://optout.33across.com/api/optout/ http://optout.33across.com/api/optout/ * http://www.quantcast.com/how-we-do-it/consumer-choice/opt-out/status http://www.quantcast.com/how-we-do-it/consumer-choice/opt-ou... * http://a.rfihub.com/oo.gif?cbust=1283182101220 http://a.rfihub.com/oo.gif?cbust=1283182101220 * http://ads.pointroll.com/privacy/opt.asp?opt=out http://ads.pointroll.com/privacy/opt.asp?opt=out * http://servedby.advertising.com/optout http://servedby.advertising.com/optout * http://ad.yieldmanager.com/opt-out http://ad.yieldmanager.com/opt-out * http://www.burstnet.com/cgi-bin/opt_out.cgi?nocache=3.173465E-02 http://www.burstnet.com/cgi-bin/opt_out.cgi?nocache=3.173465... * http://www.adbrite.com/mb/unset_targeting_cookies.php http://www.adbrite.com/mb/unset_targeting_cookies.php * http://www.yumenetworks.com/optout.php http://www.yumenetworks.com/optout.php * http://www.navegg.com/en/exit http://www.navegg.com/en/exit * http://rt.displaymarketplace.com/optout.html http://rt.displaymarketplace.com/optout.html * http://www.tattomedia.com/about_us/optout.php http://www.tattomedia.com/about_us/optout.php * http://adinterax.com/optout.phtml http://adinterax.com/optout.phtml * http://ads.lucidmedia.com/clicksense/optout http://ads.lucidmedia.com/clicksense/optout * http://adshuffle.com/optOutComplete.html http://adshuffle.com/optOutComplete.html * http://log.doubleverify.com/optout.aspx http://log.doubleverify.com/optout.aspx * http://www.dotomi.com/opt-out-yes.html http://www.dotomi.com/opt-out-yes.html * http://us.intellitxt.com/intellitxt/switchctxthist.asp?state=off http://us.intellitxt.com/intellitxt/switchctxthist.asp?state... * http://www.effectivemeasure.net/optout.php?url=http://www.effectivemeasure.com/opt_out_confirm.html http://www.effectivemeasure.net/optout.php?url=http://www.ef... * http://www.flashtalking.com/optout_cookie.php http://www.flashtalking.com/optout_cookie.php * http://www.weborama.fr/cgi-bin/set_cookie_optout.cgi http://www.weborama.fr/cgi-bin/set_cookie_optout.cgi * http://recs.richrelevance.com/rrserver/opt_out?rrnaioptout=1&nocache=0.9835474 http://recs.richrelevance.com/rrserver/opt_out?rrnaioptout=1... * http://www.tumri.com/opt-out-status http://www.tumri.com/opt-out-status * http://apps.pubmatic.com/optout.jsp?action=optout http://apps.pubmatic.com/optout.jsp?action=optout * http://api.aggregateknowledge.com/optout http://api.aggregateknowledge.com/optout * http://rotator.adjuggler.com/servlet/ajrotator/optout?action=set http://rotator.adjuggler.com/servlet/ajrotator/optout?action... * http://www.admeld.com/opt-out.html http://www.admeld.com/opt-out.html * http://ads.brand.net/optout?http://www.brand.net/index.php?option=com_content&view=article&id=151 http://ads.brand.net/optout?http://www.brand.net/index.php?o... * http://casalemedia.com/optout/?from=optmd http://casalemedia.com/optout/?from=optmd * http://app.scanscout.com/ssframework/dt/userOpt.png?a=out http://app.scanscout.com/ssframework/dt/userOpt.png?a=out * https://www.outbrain.com/privacy?opt=true https://www.outbrain.com/privacy?opt=true * http://b.xgraph.net/placeXOO.jsp?op=add http://b.xgraph.net/placeXOO.jsp?op=add * http://ib.adnxs.com/optout http://ib.adnxs.com/optout * http://ads.bridgetrack.com/optout.htm http://ads.bridgetrack.com/optout.htm * http://www.proximic.com/info/optout-success.php http://www.proximic.com/info/optout-success.php * http://px.owneriq.net/segment/optout http://px.owneriq.net/segment/optout * http://info.sv.us.criteo.com/pyz/dis/optout.aspx?o=1&l=en&cb=92664281208 http://info.sv.us.criteo.com/pyz/dis/optout.aspx?o=1&l=e... * http://img.pulsemgr.com/optout?optout&action=ooatt http://img.pulsemgr.com/optout?optout&action=ooatt * http://opt.w55c.net/out http://opt.w55c.net/out? * http://www.scorecardresearch.com/OptOut.aspx http://www.scorecardresearch.com/OptOut.aspx * http://www.dapper.net/optout.html http://www.dapper.net/optout.html * https://admin.valueclickmedia.com/optout/optout.html?uid=783125905 https://admin.valueclickmedia.com/optout/optout.html?uid=783... * http://assets.invitemedia.com/opt-out.html http://assets.invitemedia.com/opt-out.html * http://www.beencounter.com/?page=no-track http://www.beencounter.com/?page=no-track * http://tracking.vindicosuite.com/Tracking/Optout/?o=1 http://tracking.vindicosuite.com/Tracking/Optout/?o=1 * http://a.netmng.com/optout.php?op=optout http://a.netmng.com/optout.php?op=optout * http://g.adspeed.net/ad.php?do=optout http://g.adspeed.net/ad.php?do=optout * http://privacy.traveladvertising.com/Pixel.aspx?optout=true http://privacy.traveladvertising.com/Pixel.aspx?optout=true * http://gbid.adbuyer.com/opt-out http://gbid.adbuyer.com/opt-out * http://pixel999.everesttech.net/999/optout?url=http%3a//efrontier.com/optout-success http://pixel999.everesttech.net/999/optout?url=http%3a//efro... * http://alps.adchemy.com/alps-cs/auuid/opt-out http://alps.adchemy.com/alps-cs/auuid/opt-out * http://a.ctasnet.com/a?t=o&track=no&noads=all http://a.ctasnet.com/a?t=o&track=no&noads=all * http://help.aol.co.uk/technical/how-do-i-opt-out-of/article/20080430103709990004?set=WlOptOut http://help.aol.co.uk/technical/how-do-i-opt-out-of/article/... * http://a2.raasnet.com/a?t=o&track=no&noads=all http://a2.raasnet.com/a?t=o&track=no&noads=all http://jdn.monster.com/render/nano.aspx?f530b397-a781-4f9b-8e44-14bdfa1d54f9~0~0~1265315560380~480~http%3A//can.monster.com/cookie-technology.aspx%3F&optout=true http://jdn.monster.com/render/nano.aspx?f530b397-a781-4f9b-8... * http://o1.qnsr.com/w3c/optoutnow.html http://o1.qnsr.com/w3c/optoutnow.html * http://d.adgear.com/optout http://d.adgear.com/optout * http://www.hurra.com/cgi-local/opt-out.cgi?opt-out=yes http://www.hurra.com/cgi-local/opt-out.cgi?opt-out=yes * https://web.snoobi.com/en/info_optout2.php https://web.snoobi.com/en/info_optout2.php * http://optout.yieldoptimizer.com/optout/nopt http://optout.yieldoptimizer.com/optout/nopt * http://optout.mxptint.net/optout.ashx http://optout.mxptint.net/optout.ashx * http://pix.esm1.net/k/optout/optedout.php http://pix.esm1.net/k/optout/optedout.php * http://t.tellapart.com/btexclude http://t.tellapart.com/btexclude * http://www.mixpo.com/optout/nai_optout http://www.mixpo.com/optout/nai_optout * http://t.mookie1.com/o/optout/cookies/mig http://t.mookie1.com/o/optout/cookies/mig * http://qjex.net/optout.php http://qjex.net/optout.php * http://spongecell.com/opt_out/cookies_clear http://spongecell.com/opt_out/cookies_clear * http://www.lijit.com/cookie_opt_out http://www.lijit.com/cookie_opt_out * http://ad.wsod.com/?view=privacy&action=optout http://ad.wsod.com/?view=privacy&action=optout * http://a.triggit.com/optout http://a.triggit.com/optout * http://www.infectiousmedia.com/index.php/test http://www.infectiousmedia.com/index.php/test * http://tracking.quisma.com/optout.cfs http://tracking.quisma.com/optout.cfs * http://www.keewurd.com/_optout.aspx?optout=1 http://www.keewurd.com/_optout.aspx?optout=1 * http://adnetwork.buzzlogic.com/policy/cookie_opt_out http://adnetwork.buzzlogic.com/policy/cookie_opt_out * http://www.bvmedia.ca/EN/CookieOptOut/DoOptOut.php http://www.bvmedia.ca/EN/CookieOptOut/DoOptOut.php * http://brilig.com/opt_out_action.html http://brilig.com/opt_out_action.html * http://predictad.com/privacy/PrivateMode.aspx http://predictad.com/privacy/PrivateMode.aspx * http://www.chango.com/terms/opt_out_2 http://www.chango.com/terms/opt_out_2 * http://ads.newtention.net/ads/privacy?cm=optout http://ads.newtention.net/ads/privacy?cm=optout * http://tracking.reedge.com/privacy/optout.php?do=optout&redirect=http%3A//www.reedge.com/opt-out http://tracking.reedge.com/privacy/optout.php?do=optout&... * http://optout.ib-ibi.com:8000/myi-behaviorOptOut.aspx http://optout.ib-ibi.com:8000/myi-behaviorOptOut.aspx * http://a.p.mybuys.com/adn/optout?redirect=1 http://a.p.mybuys.com/adn/optout?redirect=1 * http://adserver.veruta.com/optout.fcgi http://adserver.veruta.com/optout.fcgi * http://www.wtp101.com/opt-out http://www.wtp101.com/opt-out * http://rs.gwallet.com/r1/optout?optout&r1 http://rs.gwallet.com/r1/optout?optout&r1 * http://svc.pch.com/optoutsvc/OptoutService.svc/pox/Optout?state=opt_out http://svc.pch.com/optoutsvc/OptoutService.svc/pox/Optout?st... * http://www.convertro.com/optout-success.html?cvo_optout=all http://www.convertro.com/optout-success.html?cvo_optout=all * http://www.bnmla.com/bnmla/opt_out http://www.bnmla.com/bnmla/opt_out * http://server.cpmstar.com/optout.aspx http://server.cpmstar.com/optout.aspx * http://stage.traffiliate.com/OptPut.ashx?ReturnUrl=http://www.traffiliate.com/thankyou.html http://stage.traffiliate.com/OptPut.ashx?ReturnUrl=http://ww... * http://ads.creative-serving.com/opt-out http://ads.creative-serving.com/opt-out * http://www2.glam.com/app/site/affiliate/nc/g-optout.act http://www2.glam.com/app/site/affiliate/nc/g-optout.act * http://ad3.liverail.com/privacy/?optout&yes http://ad3.liverail.com/privacy/?optout&yes * http://optout.cognitivematch.com/successOptout.html http://optout.cognitivematch.com/successOptout.html * http://nxtck.com/opt_status.jsp?language=UK&choice=opt_out http://nxtck.com/opt_status.jsp?language=UK&choice=opt_o... * http://www.demdex.net/demoptout.jpg http://www.demdex.net/demoptout.jpg? * http://d.p-td.com/r/optout?type=setOptOut http://d.p-td.com/r/optout?type=setOptOut It could be interesting if it become popular for websites to present some or all of those images to all visitors if the image size test revealed they hadn't opted out.