iwasgoodonce is correct about the "good faith" thing, if someone has bought it off the theif or the fence and bought it not knowing it was stolen then technically he is the legal owner, that absolutely sucks but how do you really know?
Is that definitely right? - I've seen no end of stuff about people that have bought cars, caravans etc that have turned out to be stolen, and as soon as the rozzers confirm the identity it gets taken away and the owner's money is lost.
the reason i believe this is because a similar thing happened to a customer while i was in the trade (only 2 years ago) orange 5 stolen from a car in the new forest, bike sold locally via ebay, bought by local who wanted some work doing on it, took it to a shop who then phoned us, we identified the bike as the customers. when we asked the local plod for an opinion what to do they said, has the customer replaced the bike? answer was yes, said if the bike was recovered it goes to the insurance company for the customer to buy back (or not) if you don't involve the police and insurance then the scroat who bought it is the new owner unless he's dumb enough to admit he knew it was stolen which implies no "good faith" and therefore incriminating. but not many people would admit that they knew it was stolen hence the "good faith" problem.
i think it works a bit different with cars etc because they are so much easier to trace with so many numbers etc allover them as well as being on databases everywhere, dvla and insurance etc. bikes are not so it almost comes down to who the coppers believe.
crap really, i think if you can proove it is yours regardless of what someone else has paid for it you should have every right to have it back, even if you have replaced it. my attitude is that it is tough luck if you have bought something that is stolen and it gets taken off you, you should have known better and if you didn't then you are probably a horrible little git anyway!
i hate theives.
You have enemies? Good. That means you've stood up for something in your life.