To shout at someone unnecessarily.
Shouting at someone unintentionally, as if your internal "caps lock" was accidentally struck.
"Dude, I'm right in front of you...stop cap-locking me!"
"Did you see Brad cap-locking that waitress for no reason?...what a jerk!"
"That Slipknot concert has jacked up my hearing, bro...I've been cap-locking people all day without knowing it...I feel like a pint-sized Lou Ferrigno."
2. One who voluntarily locks himself in front of his computer screen all day writing uneventful blog posts, commenting on blogs, trolling the internet, etc.
MrBabyMan is such a caplock; he spends is days posting articles on Digg and engaging in wikipedia edit wars . . . I wonder if he ever leaves his house.