A meaningless acronym which most often stands for "Oh My God What The Fuck Barbeque." It most likely originated on Something Awful
(somethingawful.com). It can be interpreted simply as gibberish, or used when one wants to emphasize one's own incoherence, lack of understanding, or to mock others.
It usually has an air of mockery, specifically with regard to teenagers who a lot of use three-letter acronyms.
Example #1 (def: incoherence)
Computer Nerd #1: I mean, just because it's https doesn't mean it's fucking legit
Computer Nerd #2: Yeah, I'm sure those idiot script kiddies
would love to get their hands on a secure server so they could grab some more AOL passwords before they hit up the child pr0n
Non Computer Nerd: OMGWTFBBQ please kill me
Example #2 (def: mockery)
Teenager #1: so i was all like, stacy, if u want a loser like steve for your boyfriend go ahead!!!!
Teenager #2: lol
Teenager #3: omg i can't believe u said that!!
Cynical Generation X-er: OMGWTFBBQ