Taken from the movie "Bowfinger", it's the moment in the movie where the good guy gives a gesture of triumpant defiance to the bad guys who have lost or are just about to lose.
Anything that is not acceptable or violates the g code. This includes snitching. Switching up on your true homies. Backstabbing. Acting funny. Hating. Gossiping or any other dishonorable fake shit.