JINAN,China - When Chinese police beat elderly former professor Sun Wenguang so badly they broke four ribs, it was just part of the price he has paid for a lifetime defying authority.
The white-haired, soft-spoken Sun first went to prison nearly 50 years ago and is now one of China's oldest activists, admired by the younger generation for his doggedness.
He turns 80 next month but still persists in simple acts of protest, dodging minders in a risky game of cat and mouse.
"I am, in their view, a bastard who just won't stop," he says, chuckling in his study late one night after his monitors had left.
"If my rights are infringed then I have to fight back. I can't just give up my rights."
Sun is kept under regular surveillance by Chinese authorities, with a round-the-clock guard posted at his apartment at sensitive times.
During the trial of former politician Bo Xilai in his home town of Jinan last month, a minder planted himself directly outside the door to prevent it even opening.
It was the sufferings caused by the Mao Zedong's disastrous 1958-61 Great Leap Forward and 1966-76 Cultural Revolution that turned Sun, then a university teacher of physics and economics, against the Communist party.