Just saw this thread on the BitcoinTalk Forums:https://bitcointalk.org/index.php?topic=73385.0It would seem that MtGox took it upon themselves to try to confiscate some Bitcoins from an innocent user after some of the "stolen" coins from the great Bitcoinica Heist ended up in his wallet. Of course as he points out, there are any number of ways the coins could have reached him via other users and this interpretation of "good" and "bad" coins isn't helpful. I'm pleased to say Bitcoinica concurred on this point and MtGox backed down.V.