It was about time for another Brit-Brit scandal.
The on-the-rebound pop princess is causing controversy again, accused of lip syncing on stage during the Australia leg of her "Circus" tour.
According to People magazine, about 100 infuriated fans ditched Spears' Perth show Friday, blaming her subpar performance and lack of real singing. The following day, singer/songwriter John Mayer, who's also in the Outback, posted the following update to his Twitter account:
"If you're shocked that Britney was lip-syncing at her concert and want your money back, life may continue to be hard for you."
Ouch. ABCNews.com's calls and e-mails to Spears' publicist for comment were not immediately returned.
It's not the first time Spears has been accused of lip syncing, and she's certainly not the only star to come under fire for it. Below, check out a run down of five uber controversial alleged lip-syncs, and the verdict on whether or not each artist committed what many fans regard as the greatest on-stage sin of all.