Punk Rock Fight Club: It’s Real.
Officially, FSU stands for “Friends Stand United.” Those familiar with the situation call it “F**k Shit Up.”
From Rolling Stone:
FSU formed in Boston in the late Eighties. The Boston hardcore scene had already gained notoriety as a more militant offshoot of the D.C. straight-edge movement, with the band SS Decontrol, started by brawny ex-hockey player AI Barile, leading the charge. SSD and its followers, known as the Boston Crew, became notorious for painting black Xs on their foreheads before New York shows – an X, more typically drawn on the hand, signifies you are straight-edge – and beating up anyone X-free in the pit. As Curtis Casella, founder of the Boston indie label Taang! Records, notes in American Hardcore, “When [straight edge] got filtered up north to Boston, it got a little eviler.”
Any new information? That's not exactly a current article (2007… and what is with all the typos in it? Some sort of cruel Rolling Stone watermarking?)