What does Leet Haxor mean?

L0l t3h nub hu 45k3d d15 q3u5t10n 15 m4j0r NUUUUUUUUUUUUUUB Leet Haxor: Someone who - in game uses cheats or is believed to be hacking. - Formerly known as: H4x0R! Us3d By Pl4y3r!!!