Some time ago (think early to mid-nineties), I used to run a BBS. One Christmas, I logged onto another BBS based in Manchester, and they had a "Santa Chat." I tried it for a while and was so impressed by it that I decided to write my own; it was basically the gift that kept giving. You put this thing on your BBS (basically an Eliza clone) and it records the responses of the unsuspecting users to a text file (or log).
These days there are laws against recording such things, but those were simpler times, and once they realized the joke, everyone was happy, and life went on (albeit at 14.4k bps).
