Just got a disturbing message from my cousin, someone walked up to him in a Starbucks and ask if he could borrow his notebook for some Facebooking. Not to mention he wanted to plug in a thumbdrive to do something. My cousin sent him packing on his way, but he just kept going around asking people for access to their PCs. If you haven't already figured it out yet, you shouldn't let strangers use your PCs, and allowing them to plug their thumbdrives into your system could be just allow them to get a trojan into your system. So remember.
DON'T LET STRANGERS USE YOUR PC!