Someone who runs around to all the video's of gangs on youtube talking bout how he runs all the gangs in that specific city. Then, when someone calls him out on some real stuff, he blocks them from posting on his page and claims to have "peeled their cap" which is why they don't post on his page anymore. Aka Datsniggawater wwwwwww youtube.com/user/datsniggawater
Just head over to youtube and search for some cat named Datsniggawater, all the example you need of a youtube gangster.
Some one who talks tough on youtube. They will say anything in the comments section of youtube. Threatening guns, talking about drugs and generally saying something remotely related to the video that makes them sound tough.
This fag youtube gangster just wrote "id shoot 2Pac in the face, that nigga was a lil bitch and i woulda fucked him up"