Not me but my professor.

I was taking a class on Forensic Science (studying communications at an art school, had to take 1 science-related course as a gen ed requirement, it looked fun). Our midterm exam involved analyzing handwriting in a ransom note. The professor wrote the note himself in very chicken scratch-y handwriting and made photocopies for each person a couple minutes before the exam started. Unfortunately, since he was in a rush to get to class so we could begin the exam, after he made the copies he forgot to take the original out of the photocopier.

Half an hour later when another professor went to make photocopies, she found a crudely written note that said something along the lines of, "My final demand is $50,000. If I do not receive the money by 5:00 this evening, I will detonate the bombs I have placed throughout the building." Needless to say, police were called, an anti-terrorism unit showed up, and we had to evacuate while they placed the campus on lockdown. We never ended up finishing our midterm, but as far as I know once the professor explained what had happened everything was fine and he kept his job. Pretty sure the school was on the hook for some $$ though.