Re: @Stuart22, AC
OK, so some bikes have stamped frame numbers.
First of all, are these a legal requirement?
Are these held centrally like car VIN details?
Are they required to be tied to a specific identity/registration document?
No, no, no & no. But that is irrelevant. Nearly all bikes are marked by the manufacturer. You can get it marked by the police too in London and probably elsewhere. If they are stolen they do, if the police can be bothered, go on to the stolen database. So, if I'm stopped they should be able to quickly establish if the bike was stolen and who from. Just like a Range Rover or BMW.
There are well known places where dodgy bikes are traded. These are very thinly policed because of scarce resources. But if we can find resources for reclaiming vanity cars it must be of even greater value to reclaim essential transport? Probably in greater numbers. More cases solved. Better result unless you are looking at book value.
Or is the negativity in the voting above reflective of the values of our society of which the police are just a part?