There was a nasty incident a couple of years back where an arsehole cross subscribed an aviation mailing list with AFAIR a gay porn list and racist "kill asylum seekers" list.
The dilligent and capable SysAdmins (some of whom are also PPRuNers) successfully identified the perp (after a lot of detective work) and a bright young graduate had his career in the City abruptly terminated.
I could draw the attention of said PPRuNers to this thread if it is important enough.
W