Thank you very much for your responses moonlit and digip.
The reason I was asking was because I think someone used a hacksaw or switchblade hack on my computer and, although I don't think I lost any serious information, I wanted to find out if there were ways to better secure one's USB hubs. I talked to a friend and he said disabling AutoPlay for my CD-ROM would be the best solution. I have another question, just out of curiosity - are there any log files that keep track of storage devices that were at some point in time connected to a computer, like a log containing times during which USBs were inserted into USB hubs?
Thanks