Someone who only talks shit on Twitter
“I mean, he’s a girl, man. Who does stuff like that?” “If he has more of these things to say, he can say ‘em to my face. Don’t be no Twitter gangster man.”
A person who talks a big game/talks smack on a social networking site, but most likely never confront someone face to face. Used by Giants DE Osi Umenyora when describing Philadelphia Eagle LeSean McCoy's derisive posts labeling him a "soft."
Marco was being a twitter gangster when he ripped Jack for cockblocking at the the club, be we know that bitch would never step up in real life.