I can't believe how many people there are supporting rollbacks (even if it's targeted rollbacks to a small set of transactions) in this thread. It completely undermines the blockchain.
No one could trust that their transfers for goods/services would be final.
If we were to have such a policy, how would we decide which balances were the stolen ones? How would an innocent person accepting funds from those balances for legitimate trade of goods/services know that those balances were tainted before accepting them? Or do we just accept that those people (who didn't take an extra risk by trading on a centralized exchange) are going to lose for the benefit of bailing out the unfortunate victims who knowingly took the risk to trade on a centralized exchange?
Also, who is the authority that decides/confirms which balances were stolen, the stakeholders? If so, what quorum is necessary? Even if it is 75%, you risk having the other 25% dump the stake after the hard fork because of such an extreme change in policy, crashing the price. So then maybe a 95% quorum is necessary. But that is a ridiculously high percentage that is unrealistic to ever reach. Especially considering that the people most likely to vote for the hard fork are the people who lost their money (and therefore don't have the funds to vote with).
No rollbacks! The solution is to reduce our dependence on centralized exchanges.