Taylor Swift has declared war on unauthorized online merchandise.

According to Buzzfeed, the country-turned-pop superstar's lawyers issued a series of cease and desist letters to a number of fans who were using the craft website Etsy to sell their own Swift-related creations, which had not been licensed by the singer or her representatives.

Swift just recently applied for trademark protection for various phrases related to her music, including “This sick beat,” “Party like it’s 1989″ and “Nice to meet you. Where you been?” And while it doesn't appear that any Etsy sellers have yet been subjected to any actual legal action, many popular Swift-themed items have already been removed from the site. One online seller tells Buzzfeed that receiving the warning has tarnished her feelings for Swift, since she originally began selling her T-shirts bearing Swift's lyrics out of admiration.

"Obviously an artist has a right to their art and people should respect that," she says. "But at the same time most people, like us, are trying to be respectful and contribute to the excitement that the artist brings into our lives. When that is taken away, it leaves us with a bitter taste in our mouths. It feels as though we don’t matter, that our ideas and thoughts and creations never belonged to us in the first place. No matter how hard we worked. And for other fans who make art, I’m afraid that this is going to be the future."

Swift has asserting more and more control of her music and likeness recently. In addition to applying for protections for certain phrases, she already owns a string of trademarks related to her name and music. Last November she also pulled her entire recorded catalog from Spotify, the world's largest streaming service, citing objections to the site's royalty structure, which she believes de-values an artist's work.

"Music is changing so quickly, and the landscape of the music industry itself is changing so quickly, that everything new, like Spotify, all feels to me a bit like a grand experiment,” Swift explains. “And I’m not wiling to contribute my life’s work to an experiment that I don’t feel fairly compensates the writers, producers, artists and creators of this music. And I just don’t agree with perpetuating the perception that music has no value and should be free.”

Whatever Swift's motivation for her recent business decisions, they appear to be working. Her first official foray into pop, '1989,' was the best-selling album of 2014.

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