Taylor Swift writes song about John Mayer?

Taylor Swift has reportedly criticised John Mayer in a song from her new album. Earlier this year, it was reported that Mayer had told a friend that he had "tied in" with Swift in January. People reports that the song 'Dear John' is a ballad which includes lyrics about an older man who "messed with" a young girl with his "dark, twisted games". Perez Hilton also says that Swift had hinted that her album would be full of songs which represent real relationships, and would use real names of some of her partners.