I thought the same thing at first, but imagine if somebody hacked an online real estate trading site and sold a house that wasn't theirs and tried to run off with the money... Or somebody hacked an etrade account that had 100 billion Yuan...  Similar measures would be enacted. 

I didn't really take the sell off seriously, personally, everyone seemed to be aware that it was stolen BTC being sold off.  I was surprised when they announced the 'rollback' (unfortunate wording, I would say... I would have called it a 'reversal').  Before this I thought only Wal-Mart did rollbacks.  However, at this point, I'm pleased that a reversal is possible.