I was working the late shift back in 2000 or so, and it was a slow night. As a project, I started testing out Netmeeting for video conferencing as it was something the company was interested in. Back then, Netmeeting was essentially a bunch of public chat rooms, and you could enter and leave them to start video conversations as you wished.
Well, my head is planted in a manual about setting room permissions, and "unbeknownst" to me, some naked dude popped in my room for a little fun. And another. And another. I'm reading away, and one of my co-workers walks in behind me.
All I hear is "AWWWW! YOU i love you!!!!" and he runs out. I look up, startled, and see a bunch of fat hairy guys rubbing their nipples and suggesting they stick objects into each other's orifices. I screamed like a girl and slammed the power button on my PC
3 minutes later, I hear the night manager over the company intercom "Attention: will all butt-monkeys please report to my office."
I had to go in there, explain what happened, and was laughed at mercilessly for weeks. In fact, I've been there 13 years now and that incident still comes up at least twice a year.
:$ x 10000