If you say that someone is fair game, you mean that it is acceptable to criticize or attack them, usually because of the way that they behave. Politicians were always considered fair game by cartoonists. if someone or something is fair game, it is acceptable, reasonable, or right to criticize them
a person who is the aim of an attack (especially a victim of ridicule or exploitation) by some hostile person or influence; "he fell prey to muggers"; "everyone was fair game"; "the target of a manhunt"