In University at the freshman residence, false alarms were constant. Eventually the administration sent out a memo that all of the alarm units were rigged with an invisible power that could be detected under a UV light. If you pulled the alarm, your hand would be covered in it, and once evacuated, all residents were subject to a UV scan to identify the culprit.
I was in the senior residence at the time and never found out if this was true or not, but they sure did make those kids suffer outside in the cold for a long time.
