Even better on the buying side, though, to quickly check if a bike is stolen before buying a used bike from a shop or off of Craigslist.

Yeah, I was aiming at high visibility research for Craigslist shoppers. I'm limited by Twitter, but luckily the bikeindex site looks good on mobile too.

Love the idea but can't totally grok the incentive to lookup the stolen status as a buyer. If I'm getting a good deal why would I care?

1. Reporting stolen bikes makes it harder to sell stolen bikes, making bike theft less profitable - and ultimately making it less likely that you'll be looking for a good deal on a new bike, since your old one won't have been stolen.

2. Some people actually do care.

3. Buying stolen property is illegal

isn't (3.) 'knowingly' buying stolen property that is illegal? but 'unknowingly' buying stolen property would at worst mean you will have to surrender the property to the original owner?

You should register it before it gets stolen, so that you have all the important information if it does. https://bikeindex.org/bikes/new (you have to create an account)