Yesterday, NY Times media writer Brian Stelter did a story on how TMZ, with its web site and daily TV show, “cemented its position this year as the celebrity news site to beat.”

That was yesterday. Today, TMZ proved itself as yet another news source that should check the facts before going to print.

TMZ loves to post “gotcha” stories, so when someone gets them, a grin goes across the face of other media outlets. Such an instance occurred today when TMZ was trumpeting a black-and-white photo it claimed showed President John Kennedy lounging on a yacht while two naked women jumped off the side to cavort in the water. The headline read “The JFK Photo That Could Have Changed History.” It was accompanied by text claiming that two Kennedy biographers and a forensic photo expert had examined the picture and declared it authentic.

Wrong. The photo was actually from a spread in Playboy magazine in November, 1967 — four years after Kennedy was assassinated. The Smoking Gun, calling it “a collossal screw-up,” has the story and the original photo. In color.

Almost 11 hours after posting their “exclusive,” TMZ admitted it had been hoaxed.