This form of attack is used to reduce the effect of bodyguards on a player. Bodyguards make it difficult to Wack a player, but players can work together to BG Wack another player until their Bodyguard count is low enough for a successful Wack. The strength of your Wack Skill dictates how much damage you deal to your target's BGs. A highly skilled marksman may be capable of killing multiple bodyguards in a single bodyguard wack.
Rules regarding shooting are player made and enforced. New players are strongly advised to seek guidance from their crew leaders regarding the use of their gun before attempting to bodyguard wack. It is extremely likely that "wrongful" shootings will be punished by death.