Mark Pilgrim came across a wav of someone shouting ‘Hey! I'm looking at gay porn!’ in his referrer logs. A co-worker at a previous job once encountered this file in his inbox. Of course, the fates being as they are, he encountered it precisely at the moment the managing director of the company was in an adjacent office.
Soon after this, we discovered a whole bunch of new entries in
/etc/aliases. Every incoming mail was being silently redirected to the director's inbox. By the next staff meeting, he had a list of all the distribution- and mailing-lists we were to get off now. Needless to say, that's about when I started looking for a new job. Aside from the issue of having what we thought was private mail silently redirected, we all (well, with one significant exception, but that's a story for another day) worked our asses off, and he wanted to begrudge us the five minutes a day it took to read a few jokes.