Originally Posted by Myosmith

There are a couple of disturbing trends showing up in the city. The first is the theft of seatposts and seats, especially if they have a quick release. Someone will take a parking place next to a bike rack in an affluent part of town and can have several expensive seatpost/seat combos in his back seat before anyone notices. As bike owners have caught on, some take their seat posts with them, which is good, but it also makes it hard to tell who is a theif and who is just a cautious owner when you see someone carrying one away from a bike rack.

A more disturbing trend is for would-be thieves to badly vandalize any bike they cannot steal. If they can't cut or shim a big U-lock they will use it as a fulcrum to damage frame and wheel. If they can't easily cut through a big cable lock, they'll cut spokes, cables and chain and take a few whacks at the top tube before walking off. It's as if they are punishing the owners for thwarting them.