Yeah just that you cannot legally give away stolen funds...so the miners would make themselves legally vulnerable.
Vulnerable to what, a lawsuit? That's about as fanciful as the idea the
daoattacker will sue the Ethereum Foundation really. It would also bring in to question the whole legality and regulation (or lack thereof) of TheDAO.
This doesn't mean I think they'll accept it of course.
If mining is decentralized, I think it is impossible to enforce a court decision on the miners because new miners can pop up any where. You'd need some totalitarian total world control over the Internet and block the protocol.
Doesn't seem plausible near-term in current state of the world.
More likely any court decision would be enforced on the exchanges. New exchanges could pop up, but they can also be regulated.
Perhaps any class action suit if any might attempt to name any of those prominant insiders who have profited by promoting and selling ETH such as Vitalik, Tual, etc.. I am not sure if a lawyer would advise that or not, and whether it could be successful. I hope they've retained counsel.