Road Bike or MT Bike for College?

I went to the University of Colorado at Boulder, and rode a CHEAP mountain bike. Bike theft is a big deal at colleges. Spend at least 20% of the cost of the bike on a "U" type lock, and run it through both frame and front wheel. Back wheels are hard to steal, and not worth effort on inexpensive bikes. Get a locking seatpost too. Somebody stole that off my bike and it was NOT a fun ride home.