I'm a grad student at UNC. Last week I pulled a close-to-all-nighter, in my office until 4 AM. I'd left my commuting bike locked up by the library, and there were other bikes locked there as well. But when I came out to my bike, all was not well.
The front and rear lights, and speedometer, had been removed from their brackets on the bike, and smashed on the ground. I picked up the pieces as I could find them, then found that the rear wheel was rubbing on the fender. The fender stays had been bent, and the rear wheel was somewhat out-of-true, perhaps from the same kick. I bent the fender stays back enough that I could ride the bike home.

I was able to true the rear wheel, glue the lights back together, and had to install a new speedometer.

But I also noticed that the drive-side seatstay had been bashed in. With something heavy, perhaps a pipe wrench. (pictures attached)
The rear wheel is slightly out of alignment as a result of the frame damage, but not much - I can still ride no-handed, and bending the frame back may further weaken the seatstay-seat collar joint. I'm just going to check the frame once a week or so,

I've seen bikes with their wheels kicked in, and have always wondered why people do something like this. What do they get out of it? I don't think that they were trying to steal bikes, as other bikes were locked to the same rack with cable locks (while mine has a U-lock).