Matt Furie created the cartoon character Pepe the Frog in 2005 for his comic book Boys Club. In 2008, Pepe started showing up in memes on the anything-goes Internet message board, 4chan. But during the 2016 election, Pepe was adopted as a kind of mascot by members of the alt-right, who used the symbol to demonstrate support for racism and white nationalism (as well as the candidacy of Donald Trump). As a result, the Anti-Defamation League now characterizes Pepe as a hate symbol. Fed up with how his creation has been co-opted, Furie is intent on taking Pepe back, according to Ars Ttechnica.

To do so, Furie has hired a lawyer and sent warning letters to several alt-right personalities, such as Mike Cernovich, white supremacist Richard Spencer, and the popular subreddit “The_Donald.” The letters demand that they remove all images and videos including Pepe. The letter also states that Furie is entitled to damages because of the copyright infringement, and that once the images have been removed, Furie’s lawyers will contact them to discuss the appropriate amount.

While the odds of staunching all online use of Pepe for hate messaging is slim—the warnings spawned a defiant surge in Pepe’s use by alt-righters in response—Furie has had some success in commercial misuse of his image. Last month, a man in Texas who created an Islamophobic version of Pepe for a children’s book settled with Furie for an unspecified amount.

Furie’s lawyers told Vice that they want to “make it clear that Pepe was not the property of the alt-right and couldn’t be used by the alt-right,” reports Ars Technica. Some in the alt-right who used Pepe have taken the images down, but Furie’s lawyers “plan to take action if they don’t.”

Cernovich also took down the images, but he published a response by his own lawyer, Marc Randazza, which says that “Furie won’t see a dime from Mr. Cernovich.” He also claimed that the letter was not “a serious legal threat” and that the image of Pepe qualifies as fair use.

Another main alt-right user of Pepe, known online as “Baked Alaska,” laughed off the legal threat as invalid. But that was based on his apparent misunderstanding of the difference between trademark and copyright. He tweeted that “Matt Furie was too dumb to realize his trademark for Pepe the Frog has been expired since Oct. 2016. False DCMA claims are strong violations.” But another Twitter user pointed out that “copyright is not the same as a trademark.”

Matt Furie was too dumb to realize his trademark for Pepe The Frog has been expired since Oct 2016. False DCMA claims are strong violations. pic.twitter.com/B3S4Dk3rVX — Baked Alaska™ (@bakedalaska) September 18, 2017