The feud between rival pop princesses Katy Perry and Taylor Swift certainly seems to be heating up. The latest development in the spat is KP has registered the song title '1984' with BMI records. A move, which many are claiming, is a dig at Taylor's latest album and tour title 1989. Katy's fire back comes hot on the heels of the release of Taylors number one hit 'Bad Blood', which is about a friendship gone bad, apparently based on their relationship. While 25 year old Taylor has never directly confirmed that her latest hit is about Katy, she did tell Rolling Stone magazine in an interview before 1989 was released that Bad Blood was about another female performer, describing their relationship as "straight-up enemies."