According to
these reports in
The New York Times, Chinese authorities are more or less systematically detaining critics, notably artists and writers. Prominence seems no longer to afford any protection, as the regime has detained even the very visible artist
Ai Weiwei. (This
helpful post at
The New Yorker provides some context. This is not the first time he has had run-ins with the authorities - you can find a digest
here at
The Guardian.)