Taylor Swift's Jihad Against Alleged Topless Photo

The photo in question features a topless woman who bears a resemblance to Swift under the headline, "Taylor Swift Topless Private Pic Leaked?"

Swift's lawyers are pissed -- and fired over a letter to the site demanding it take down the post immediately ... or else she'll sue for trademark infringement.

In the letter, Team Swift says the site contains, "false pornographic images and false 'news" about the singer.