Are pictures of naked people on the Internet a new agent for social change? Maybe not in general, but for Egyptian blogger Aliaa Elmahdy, as well as some supporters of dissident Chinese artist Ai Weiwei, nudity has suddenly become a way of registering discontent.

Elmahdy, a 20-year-old former student, made waves in Egypt after a friend posted a photo of her naked on Twitter late last month, with the hashtag #nudephotorevolutionary. She told CNN that she asked her friend to post the picture "because I am not shy of being a woman in a society where women are nothing but sex objects harassed on a daily basis by men".

Reactions to the posted picture have varied widely. Some have praised Elmahdy's actions: Egyptian-American journalist Mona Eltaway wrote "she is the Molotov cocktail thrown at the Mubaraks in our heads", comparing her actions to those that helped to depose Hosni Mubarak. As the Economist notes, "her detractors have, predictably, damned her as an attention-seeker, a disgrace or a pervert". One thing is certain: she's getting a lot of attention.

In China, meanwhile, over 70 of Ai Weiwei's supporters have posted nude shots of themselves on a website called 'Ai Wei's Fans' Nudity - Listen, Chinese Government: Nudity is not Pornography'. The site was created in protest after Beijing police questioned Ai's videographer for allegedly spreading pornography online after taking nude photographs of Ai and four women. Ai is currently facing a $2.4 million tax bill from the Chinese government that his supporters say is politically motivated, and the interrogation is seen by those supporters as China's latest attempt to silence its most famous social critic.