Acronym standing for "Between Keyboard And Chair."
Mainly applies to AOL users, who complain how something does not work, and tend to blame it on the software/hardware. 99% of the time, the problem is BKAC, meaning it is the user.
AOLUSER9120: OMG LIEK MY MOWSE WONT WORK THEIR IZ PROBLEMZ LOLOLOL!!!
Tech Support: Is it plugged in?
AOLUSER9120: OMG LIEK NOEZ WTF R U TALKIN BOUT DAWG?
Tech Support: Problem is BKAC *hangs up*
AOLUSER9120: OMG HE IZ GAYY