In college, during Novell's heyday, I was working on my Certified Network Administrator certification (totally worthless, in retrospect). As I was becoming an expert in all things Novell, I found a security flaw. Using Visual Basic it was possible to code up an exact replica of the Novell login screen that launched at boot time from a batch file stored on a floppy. You could log peoples' usernames and passwords all day as long as they didn't realize your floppy was in the drive, which worked in certain computer lab setups on campus. I wasn't in it for stealing info or being a criminal. I just did it for the lulz. But if I had gained access to a few of the right computers in admin offices on campus, I could've gotten access to anyone's student profiles and grades.