have you ever wondered if the bike rider has stolen the bike?

[kenyonchris]

Sorry for the hijack, smilingcat, but a quick question to chris about running serial # of bikes. Is there a national police databank of stolen bike serial #s?

There is a crimes database of serial numbers of stolen things....bikes included. If your bike is stolen and you have the serial number and it is included in the theft report, it will be crossmatched in the database. If it is recovered (ditched or seized), or entered by a reputable pawn shop, or a detective runs across a suspicious looking item in a pawn shop, or an attentive police officer has reasonable suspicion that a bike may be stolen, they can cross reference it and check.
Sadly very, very few people have the serial numbers of their stuff. Therefore, not much of it is recovered.