There was an interesting thread on Security Focus about this. One of the arguments is that "black-hat" worms are usually released first (thus causing damage) before the "white-hat" worm. Why not use auto-update instead of waiting for worms in the first place? If anyone is interested, I can post the entry here.
Personally, I don't like any worm taking over my computer, I look carefully at what auto-update is doing for the same reason.
James P. Cottingham
When a man sits with a pretty girl for an hour, it seems like a minute. But let him sit on a hot stove for a minute and it's longer than any hour. That's relativity.
[tab][tab]Albert Einstein explaining his Theory of Relativity to a group of journalists.