From the Associated Press (link):
A prominent human rights lawyer was detained by police on Saturday as China continued a crackdown on protests ahead of the opening of parliament.
Gao Zhisheng said plainclothes policemen and state security agents accused him of taking pictures of them.
"They started pushing me and trying to twist my arms around my back," Gao said in a telephone interview. "As more and more people gathered, they started shouting that I was a mad person and tried to pin me against a wall."
Gao said he was taken to a local police station, where officers checked his camera and found no evidence of photos. He was released after two hours of questioning.