youve bought it in good faith at a reasonable price and have proof of that with no way of knowing it was stolen. Now if youve bought it for 25 from a bloke down the pub then thats a different matter. if it happened over here then you have a claim to the property and can rightfully hang on to it. the owners of it ie canon if it was stolen from them would have rights to it as well and could apply through court to hve it returned, but that is so unlikely as to be untrue, as is a knock at your door.