More than 8,000 authors have signed an open letter to the leaders of several tech companies asking them “to obtain consent, credit, and fairly compensate writers for the use of copyrighted materials in training” artificial intelligence.

The letter was posted on the website of the Authors Guild, a professional organization that advocates for causes including copyright protection. It is addressed to the CEOs of Alphabet, IBM, Meta, OpenAI, and Stability AI.

“We, the undersigned, call your attention to the inherent injustice in exploiting our works as part of your AI systems without our consent, credit, or compensation,” the letter reads in part. “You’re spending billions of dollars to develop AI technology. It is only fair that you compensate us for using our writings, without which AI would be banal and extremely limited.”

Authors who have added their signatures to the letter include Margaret Atwood, Michael Chabon, Louise Erdrich, Jodi Picoult, Diana Gabaldon, Jonathan Franzen, Rebecca Makkai, and Alexander Chee.

The letter comes on the heels of two lawsuits recently filed against OpenAI by authors. The first was brought by Mona Awad and Paul Tremblay, and the second—which also includes Meta as a defendant—was brought by comedian Sarah Silverman alongside writers Richard Kadrey and Christopher Golden. Both suits seek injunctive relief and monetary damages, claiming that the companies engaged in copyright infringement.

The Authors Guild letter asks that the companies ask for permission before using authors’ works to train AI, and pay them for their use.

“The introduction of AI threatens to tip the scale to make it even more difficult, if not impossible, for writers—especially young writers and voices from under-represented communities—to earn a living from their profession,” it reads.

Michael Schaub, a journalist and regular contributor to NPR, lives near Austin, Texas.