Randy Quaid for letting us all know that at least eight actors have been victim to this gang of 'whackers'. Aside from Ledger, the whacker gang has also had success with Chris Penn and David Carradine.
Randy Quaid and his other half, Evi, have fled from justice in the USA to the 'safer' confines of Canada. According to Randy, he is being pursued by the whackers. Presumably this means he is next in line to be whacked.
The legal troubles and the stories surrounding the Quaids just keep getting weirder all the time. The Quaids legal problems include squatting and burglary among others. The fact that they need to flee to Canada in order to avoid being whacked is icing on the weirdness cake.