A "person" (usually male) who portrays themself as a gang member, badass, or hardened criminal on internet mediums such as forums, IM, or anywhere else they can post their faggotry. Generally, they are either severely overweight or malnourished caucasian suburbanites who listen to gangsta rap and think it makes them an OG. They almost always make threats of physical violence, which is never backed up and only serves to make themselves feel tough, usually because they got beaten up a lot in school, or because they are just weak ass bitches. Will frequently tell lies about how many fights they've won, claim membership in a legit street gang, or any number of other "computer gangstaisms". If you call them on their bullshit they use their typical "thugged out" cyber-defense, but then log off and cry in the corner repeating "I am a thug...I am a thug..." over and over to reassure themselves that they are in fact gangstas. Disregard any threat they make to you and laugh at their fake machismo, it's the right thing to do.
Computer Gangsta: I'll kill you son, Straight up OG!
Human Being: Shut up bitch, the only thing you've ever killed is a box of cream puffs.
If the Crips saw that scrawny whiteboy wearing a blue flag around his face on the street, he would get his comeuppance in triplicate.
"To keep it real kid you gots to stay humble" - Everlast
Words that every computer gangsta should take to heart.