It comes from the super hero from the webcomic Cyanide and Happiness, who flies down into the scene, wearing a shirt saying "LF" on it, and promptly says "LOL!! FAG!!" to the reader/other characters in the comic, and flies off.
LF, the abbreviation for lol, fag, is often used in gaming as a burn or insult.
Short for 'Lebanese Forces'. Ultra right-wing Catholic militia notorious for it's massacres of civilians durring the Lebanese civil war and it's alliance with Israel. Merger of the Phalange, Guardians of the Cedars, National Front, and other assorted baby-killers. In short, total raving psycopaths with guns. Supposedly disarmed in 1990, it still shows up at oppurtunistic moments. Members are generally the most closed-minded and bigottous in Lebanon, and wish to return the country to Christian Hegemony.