I've seen a lot of bikes get stolen over the years, especially in the city and on college campuses. It seems like no matter if the bike is a Schwinn from the 1970's or a newer mountain bike, if it has wheels, it gets stolen.
So, what can you do about it? The answer is obvious, lock your bike. But more than just lock your bike, lock it up properly. Just locking it may be a deterrent, but not locking your bike correctly may also increase the chances of someone riding away.
This guy is a mechanic in NYC and, though loud and opinionated (it is New York after all) he's got good points about how to properly lock your bike up:
1. Make sure the pole or rack that you're going to lock to is securely planted in the ground
2. Anything you want to see again, take with you: Helmet, lights, panniers, etc.
3. Use both a strong U-lock and a cable to lock your rear wheel and the frame to the bike rack and the front wheel to the U-lock.
4. Use a smaller cable to lock your saddle to your frame, or mark your seatpost and take your saddle with you.
Until next time, ride long and keep the rubber-side down.