China-based hackers temporarily took down Change.org’s Call for the Release of Ai Weiwei petition with a denial-of-service attack. Don’t be surprised: Chinese government’s tech hounds have a documented record of DDoS attacks on expat dissidents and a “notorious pattern” of internet monitoring human rights activists.

The Guggenheim supported petition’s “unprecedented success of a campaign by leading global art museums” made it a prime target. It now has more than 93,000 signatures, but Ai Weiwei is still missing.

Hyperallergic has more updates.