Funny story over at wired. A high school thought it would be a good idea to get all their students laptops. They put filters and monitoring software on them, but of course the kids found ways around these limitations and did horrible, unspeakable things. Like download iChat.
The long and short of it is that educators, unable to stop the kids from 'breaking the rules', called in the cops.
In order for the kids to get around the barriers that educators set up, they needed to know the password. How did they crack it? From the article:
"...the password was taped to the backs of the computers."