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Paging Taylor Swift? In the early hours of Tuesday, Sept. 9, Katy Perry took to Twitter to warn her 56.7 million followers of an unnamed mean girl -- less than 24 hours after fresh speculation began of a supposed feud between Perry and Swift.

"Watch out for the Regina George in sheep's clothing…" Perry, 29, tweeted without context on Tuesday, referencing the lead character and ultimate mean girl, played by Rachel McAdams, who faced off against Cady Heron, played by Lindsay Lohan, in the hit 2004 comedy "Mean Girls"

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The cryptic words followed widespread chatter that there is tension between the "This Is How We Do" performer and Swift, 24. 

The drama started when the "Shake It Off" singer gave a revealing cover story interview for the new issue of Rolling Stone, and at one point during the sit-down, spoke tantalizingly of issues she has with another famous female artist. 

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Said artist is the subject of a song called "Bad Blood," which is featured on Swift's upcoming album, "1989." Explaining the song's inspiration, she told Rolling Stone, "For years, I was never sure if we were friends or not. She would come up to me at awards shows and say something and walk away, and I would think, 'Are we friends, or did she just give me the harshest insult of my life?'… She did something so horrible. I was like, 'Oh, we're just straight-up enemies.' And it wasn't even about a guy! It had to do with business. She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me. And I'm surprisingly non-confrontational – you would not believe how much I hate conflict. So now I have to avoid her. It's awkward, and I don't like it."

While Swift mentioned that the feud wasn't about a boy, she and Perry both famously dated John Mayer, and Rolling Stone notes that when "pressed," Swift said there was a personal aspect to the drama, "but I don't think there would be any personal problem if she weren't competitive." Both chart-topping women were also on tour beginning in February 2011, with Perry wrapping in January 2012 and Swift in March 2012.

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For her part, Swift chose not to offer further clues as to the inspiration for "Bad Blood." Other artists whose names have been included in the talk include Miley Cyrus and Demi Lovato. In an online watercooler poll at Us Weekly, 70 percent of more than 8,500 readers who voted guessed the song was about Cyrus. 


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