The 'Water Board' scam
Ten years ago I lived in university halls (Morel Hall - Oxford Brookes). The 'halls' were actually blocks of six or ten flats built in a not-unattractive ski chalet style, set in several acres of equally not-unattractive parkland.

We pulled quite a few stunts (of course, groan) but one of the best was the night my friend and I rang the block of some of the overseas students, claiming to be from the Local Water Board. My friend, who had a deeper and more authoritative voice than mine, casually informed them that their water would be turned off early the next morning and that they would have to fill their bath and large saucepans for their next day's water needs.

So off we ran, spliffs ready rolled, to sit outside their patio doors and watch them fruitlessly filling anything they could lay their hands on with ice cold water. Amazingly they never twigged that the call had been made on the internal phone system. It provided us with half an hour's hazy amusement anyway.
( The Legendary Pink Dot survived yet another, Thu 5 May 2005, 9:02, Reply)