Musicians from ABBA, Radiohead and The Cure have joined actors and authors in signing a protest letter against the mining of their artistry to build artificial intelligence tools.

Thousands of artists signed the letter released Tuesday — the latest public warning about AI tools that can spit out synthetic images, music and writings after being trained on huge troves of human-made works.

“The unlicensed use of creative works for training generative AI is a major, unjust threat to the livelihoods of the people behind those works, and must not be permitted,” says the petition.

Among the signatories are Bjorn Ulvaeus of the Swedish supergroup ABBA, The Cure's Robert Smith and Thom Yorke and his Radiohead bandmates. Also signing were writers including Nobel-winning novelist Kazuo Ishiguro and actors Julianne Moore, Kevin Bacon and Rosario Dawson.

Bestselling novelist James Patterson signed Tuesday's letter and another open letter last year organized by the Authors Guild, which later brought a lawsuit against AI companies that is still proceeding in a New York federal court.