If you don't know who Ai Weiwei is you can look him up on the internet for his amazing accomplishments and heroism [and here's one of many posts about him I've done on this blog], but the short version is he's a world renowned artist whose art I was already a fan of when he started becoming more and more politically engaged in the struggle for human rights in his native China.
He chose to confront the authorities there even though he could have moved to New York or Paris or wherever and lived the life of a highly successful artist with riches and fame. The Chinese authorities have made him pay, though not as much as they may like to (thanks in part to his international fame) by bulldozing the building that housed his art studio and putting him in prison with conditions he has only hinted at but which kept him isolated from family and friends and even his lawyer etc.
He is out but not allowed to leave the country and lives under the threat of being imprisoned again at any moment and yet he continues to speak out and fight injustice. Here's the link to his latest communication from yesterday's UK Guardian.