My first job out of college was as a entry level systems admin for Sun servers at an international bank with offices in Chicago. As the new guy, I spent a fair amount of time on the HellDesk which had Sun workstations on it.
Someone had pointed out you could just cat properly formatted audio files to the audio device and they would play. I was in a playful mood one day and I set all of the Sun workstations on the HellDesk (6 I believe) to randomly play a catcall every 10-30 minutes if I remember correctly. I didn't think much of it, since I wasn't assigned to the desk that week, and about a week later turned it off.
A few months after that I was talking with one of the women who worked the desk every day and apparently the random catcalls from various directions had been attributed to people walking around the desk and HR had been called. Luckily she and I were friends and she didn't mention my involvement to anyone.