One said it was to teach Ledger manners after 18 months of bad behaviour.
No it wasn't. It was clearly mean-spirited, childish, spiteful revenge. And for what? If they hadn't been out of bounds in the first place, Heath would have had no reason to be rude to them.
It could come back to fly in their faces, too. Thanks to stupid stunts like that, celebrities--their bread and butter--may in future be kept far away from photographers and fans at premieres for their own safety. Dumbass mules.