It came from at first from the spam skit by Monty Python's Flying Circus(UK's famous comedy TV program). In the sketch, a restaurant serves all its food with lots of spam, and the waitress repeats the word several times in describing how much spam is in the items. When she does this, a group of Vikings (don't ask) in the corner start a song:
"Spam, spam, spam, spam, spam, spam, spam, spam, lovely spam! Wonderful spam!"
Until told to shut up.
By the way, do you know the origin of the winny(the evil software)?