Mostly out of curiosity, although I'm being tempted by an example outside one of my classrooms, what do you guys think about something that's already been hit by thieves and has been sitting out for months. For example a completely stripped frame, or a frame with a fork stem and bars only, locked to something. It seems possible that the owner has been too lazy to come get their frame but on the other hand chances are even if they were theoretically planning to come get it at some point it wouldn't be made into a bicycle again. Maybe leave an official looking note with my own phone number and come back after a week or two?