There is a slight relevance of Bitcoin: Bitcoin transactions are irreversible. There is no real technical means to reverse a transaction; it is simply not possible. Even if there was a court order to reverse a transaction, unless the physical recipient could be identified, located, and arrested, the court order would be meaningless.
This is in contrast to almost any other exchange system (besides hard cash), which could, at least technically, force reversal of a transaction. See for example Paypal, Facebook credits, money in an MMORPG, shares of stock, and so forth.
It's not the exchange system that matters, it's who holds the account.
With bitcoin if I hold my coins in a currency exchange (which is basically a bank) they can obey the court order and reverse transactions.
And I can become my own bank, and then hide, in which case it would be hard to serve a court order on me. (Although banks often have accounts at the fed, so they don't hold the money themself.)
What's unique about bitcoin is most people hold their own accounts. So you have to find the account holder, which is hard. But, as I said, it's not the exchange the matters, it's the account holder.
With bitcoin if I hold my coins in a currency exchange (which is basically a bank) they can obey the court order and reverse transactions.
It would be trivial if it was that simple, but the stolen funds were of course withdrawn from Tradehill, and so are no longer in control of an exchange.
It's no different from a criminal running off with a bag of cash; how are you going to "reverse" the transaction of the money being physically picked up, put in a bag, and carted off?
If you substitute "TradeHill" for "E*Trade" and "bitcoins" for "stocks" the problem would still be the same, right?