M.I.A.? Network television? Controversy? Who would’ve thunk it, right? Actually, it should come as no surprise that some brouhaha has arisen from M.I.A.’s appearance on Letterman last week. She says the show’s producers made her alter the sound of gunfire featured in “Paper Planes.” But some kind of snapping noise is still in there, and with M.I.A. cocking her hand like a gun and threatening to “take your money,” I don’t know who any censors thought they were fooling. M.I.A. ranted about the ordeal this weekend at the Austin City Limits Festival. There are clips of that floating around out there for anyone inclined to go dig them up.