Lawful evil is a tendency in RPG alignments that denotes a lawful behavior (ethics) in the chaotic-lawful axis and evil morality in the good-evil axis.
A character in Dungeons & Dragons games with a "Lawful Good" alignment, played poorly and to the detriment of the game, usually resulting in the deaths of the character and his allies.
A play on words that seem to be referring to the dictator Mao Zedong (Tse-tung) as being a law-abiding citizen, when in fact the phrase refers to LOFLMAO, a variation of ROFLMAO, meaning LOL'ing on the floor laughing. Despite the inherent redundancy, this phrase has been slowly growing in use as internet chat rooms seek newer ways to express themselves.
chadbrochillz18: I thought the new Twilight movie was pretty good.
PeteZombie: ....orly?
chadbrochillz18: Yah, Rob Pat is on top of his game. As was Shark Boy.
PeteZombie: GTFO. NOW.
*chadbrochillz banned
bloodninja2: Lawful Mao, sir.
PeteZombie: You too.