血房地图 (blood-stained housing map / xuèfángdìtú) is a crowdsourced project by Chinese bloggers and activists that uses Google Maps “to plot violent housing evictions and land grabs across the country.”
Why it is blocked: Though the Chinese central government has at times given citizens space to air their grievances publicly regarding local land seizures (most memorably allowing state-run newspapers to report on the Chongqing “nail house" incident in 2007), a project of this magnitude—one that seeks to connect local activists with each other and perhaps develop a nation-wide movement—is bound to be censored. WSJ ruminated back in October 2010, the month the maps appeared online, how long the project would continue. The map that contains only incidents verified by the creator seems to have last been edited in November 2010, but the one open to public editing is still being updated, though most of the edits are to incidents from 2010 and 2011.
Partial key to maps: Volcano=mass incidents; bed=person killed inside the building during demolition; flame=self-immolation; “i”=unconfirmed