ABC News "Nightline" is strongly in contention for that honor with its breathless Brian Ross investigative report on Justice Scalia's Federalist Society appearance. A general hail of dead cats has descended on ABC from commentators including, among others: Tom Goldstein, SCOTUSblog; Mike Cernovich, and again at more length; Orin Kerr; Sean Sirrine, Objective Justice; Ed Brayton; and Bill Nienhuis.
Don't just blame ABC, though. Blame lawprof Stephen Gillers, who was much relied on by Ross in his report, and who's enjoyed a status in much of the press for years -- a quite inexplicable status, as this episode shows -- as the go-to guy on legal ethics. (cross-posted, and slightly shortened, from Point of Law). P.S. The Federalist Society's letter in response is here in PDF format.