Think about it this way: A thief steals a widget from you and sells it to me for $x. I have no reason to suspect it was stolen. The thief then absconds with t

Think about it this way: A thief steals a widget from you and sells it to me for $x. I have no reason to suspect it was stolen. The thief then absconds with the $x and spends it on consumable goods; even if caught, the cash can't be recovered from him. I currently have the widget and have lost nothing; you're currently the thief's only victim. But if the court takes the widget from me and gives it to you, you're fully compensated, while I am now the victim, because my $x has effectively been stolen with no compensation. In other words, there are two people who have been victimized by the thief, but all the court can do is re-assign victimhood to one party or the other, which, all things being equal, it should be indifferent to. Allowing the purchaser to keep the widget is basically the same as saying that they'll have no part in deciding who is to be the victim, and allowing circumstance itself to determine that. But the thief himself is always responsible, and it's entirely appropriate to extract from him as much compensation for both victims as is possible.