Today the Berkman Center announced a new project that might be of interest to readers. Since 2002 I’ve studied Internet filtering around the world, most recently as part of the OpenNet Initiative. Last year with support of the MacArthur Foundation we published “Access Denied,” a study of filtering in about 40 states. Our work so far has been centralized—which means that gathering the data and analyzing to a gold standard has taken months. We’re now complementing that effort with a distributed reporting system called Herdict, as in “verdicts of the herd.”

Anyone interested in helping track blockages of information around the Web can download a small add-on for Firefox or IE. Then, as you surf, an icon will change colors depending on whether the site you are visiting has been reported as inaccessible by others near you or elsewhere in the world. Data is accumulated at the main web site, producing a realtime map of reports of blockages, and there’s an “AmIBlockedOrNot” mode where you can page through sites reported as inaccessible and see whether you can load them yourself.

The hope is to gather data in near-real-time about blockages, allow people to know what sites appear to be blocked and where, and to test out the notion that distributed efforts can work in this field. This may help to enumerate “traditional” filtering—such as that done in China and Saudi Arabia (Chinese and Arabic language versions of the site are in progress)—and also more network neutrality-related issues, such as filtering in schools and corporate environments. People can also report as inaccessible material that has been taken down from a site, such as a YouTube link that no longer works, and thus show retractions of data or geofiltering—such as when YouTube blocks certain videos only for subscribers accessing from Thailand.