Computer Slang. From the Jargon file:
Sometimes uttered in response to egregious misbehavior, esp. in software, and esp. of misbehaviors which seem unfairly persistent (as though designed in by the imp of the perverse). Often theatrically elaborated: "Aiighhh!
Fuck me with a piledriver and 16
feet of curare-tipped wrought-iron fence *and no lubricants*!" The phrase is sometimes heard abbreviated `FMH' in polite company.