SeaWorld's long year of ugly public-relations setbacks just got even worse: Joan Jett has served the theme park with a cease and desist letter demanding that they stop using her music as part of one of their most popular attractions.

CNN reports that Jett sent her letter to SeaWorld CEO Jim Atchison in response to the park's use of her signature song 'I Love Rock 'n' Roll' to lead off its 'Shamu Rocks!' show. Apparently unaware that her song was part of the program, Jett wrote that she was "surprised and upset" to hear it in a YouTube clip, and found herself "sickened that my music was blasted without my permission at sound-sensitive marine mammals."

"These intelligent and feeling creatures communicate by sonar and are driven crazy in the tiny tanks in which they are confined," continues Jett's letter. "If I don't receive written confirmation that SeaWorld will cease and desist from using any Joan Jett & the Blackhearts music, I will be forced to take further action, and you'll find me among the PETA protesters outside your parks."

SeaWorld has found itself under an unwelcome spotlight in 2013 following the release of the damning documentary 'Blackfish,' which purports to expose the theme park's cruel and dangerous treatment of its staff and animals. Company representatives quickly denied the filmmakers' allegations, but their protests have largely fallen on deaf ears, and in recent weeks, a growing list of artists -- including Willie Nelson, Barenaked Ladies and Heart -- have backed out of previously scheduled SeaWorld shows.

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