Artists 4 Safe AI Hollywood open-letter release urging Governor Newsom to sign California SB 1047 (25 September 2024)

On 25 September 2024, a coalition of Hollywood actors, directors, and producers organised under the Artists 4 Safe AI banner publicly released an open letter to California Governor Gavin Newsom urging him to sign California Senate Bill 1047, the Safe and Secure Innovation for Frontier Artificial Intelligence Models Act, then sitting on his desk on a thirty-day signing clock that ran to 30 September. The release was the closing veto-eve mobilisation artefact of the Encode Justice SB 1047 co-sponsorship campaign, four days ahead of Newsom's 29 September 2024 veto, and the moment at which the broader celebrity-signatory track of the campaign — distinct from the institutional union-side SAG-AFTRA letter that General Counsel Jeffrey Bennett had sent on 9 September 2024 and from the AI-lab-employee letter signed the same day by more than 113 current and former employees of OpenAI, Google DeepMind, Anthropic, Meta, and xAI — arrived in the press cycle.

What released on 25 September 2024

Deadline's 25 September release-day coverage reported 125 industry professionals as signatories of the letter at launch. The named lead roster — carried in Deadline's report and on the letter's own landing page — included Jane Fonda, Mark Ruffalo, Shonda Rhimes, J.J. Abrams, Pedro Pascal, Judd Apatow, Mark Hamill, Ava DuVernay, Mahershala Ali, Joseph Gordon-Levitt, Don Cheadle, Jessica Chastain, Sheryl Lee Ralph, Jean Smart, Hannah Einbinder, Rosie O'Donnell, Ebon Moss-Bachrach, Allison Janney, Fran Drescher, Sean Astin, Janelle Monáe, Mariska Hargitay, Sophia Bush, Connie Britton, Alec Baldwin, Annaleigh Ashford, Alyssa Milano, Jessica Alba, Rosanna Arquette, John Cho, Jennifer Beals, and Tom Arnold. Blog.biocomm.ai had republished the letter's full text on 24 September, one day ahead of the Deadline release cycle, with a broader 170-plus signatory list that added SAG-AFTRA chief negotiator Duncan Crabtree-Ireland alongside Drescher, musicians Grimes, José González, Aloe Blacc, and Janelle Monáe, and comedians W. Kamau Bell, Adam Conover, and Rosie O'Donnell. The letter's own landing page carried the call-to-action — directing readers to peopleovermachines.org — and the running signatory list, which by the time the campaign closed had grown to 300-plus individuals and bands.

The letter the release made public is captured in detail as a standalone Publication in the corpus — see Artists 4 Safe AI open letter for the substantive content (the central framing line, the biological-weapons and critical-infrastructure risk argument, the relationship to AB 1836 and AB 2602, the 77% Californian-support polling number). This Event entry focuses on the release moment itself: who organised it, who signed at launch, what the press cycle on the day captured, and how the release sits inside the campaign's veto-eve mobilisation architecture.

Encode Justice's coordinating role

The on-record coordination of the Hollywood track sat with Encode Justice, the youth-led AI-policy advocacy organisation founded by Sneha Revanur and one of the three civil-society co-sponsors of SB 1047 (alongside the Center for AI Safety Action Fund and Economic Security Action California). Stanford Daily's 20 October 2024 retrospective carried the on-record line that "Encode Justice helped coordinate much of Hollywood's support," and named the Mark Ruffalo and Shonda Rhimes signatures among those Encode had recruited. Scott Alexander's "SB 1047: Our Side Of The Story" corroborated the coordinating role on the public record: Encode Justice, he wrote, "recruited more than one hundred members of the actors' union SAG-AFTRA to the cause." The peopleovermachines.org call-to-action site — the destination the letter directed readers to — features prominent social and video messages from Adam Conover, Mark Ruffalo, Joseph Gordon-Levitt, Sean Astin, and Piper Perabo, and tags both @sagaftra and Encode Justice as named collaborators on its public-facing pages.

The release sits on the public record as the third and largest of the three letter tracks the campaign aimed at the governor's signing decision in September 2024: the 9 September SAG-AFTRA institutional letter under General Counsel Jeffrey Bennett's signature on the union's behalf; the same-day letter signed by more than 113 current and former employees of the five named frontier-AI labs; and the 25 September Artists 4 Safe AI celebrity-signatory letter. The three tracks ran on separate covers and used distinct framings, but converged in the same fortnight on the governor's desk.

SAG-AFTRA cross-membership and the public-versus-institutional distinction

A load-bearing feature of the 25 September release is that several of its lead signatories — SAG-AFTRA President Fran Drescher, chief negotiator Duncan Crabtree-Ireland, and a substantial portion of the wider SAG-AFTRA membership — had also been the subjects of, or signatories on, the union's separate 9 September institutional letter. Drescher's signature on both letters is documented in Variety's coverage of the SAG-AFTRA letter and in blog.biocomm.ai's full-text reproduction of the Artists 4 Safe AI letter. The two letters' framings, however, were deliberately distinct: SAG-AFTRA's 9 September union letter foregrounded the deepfake and likeness-protection concerns the union had carried into its 2023 strike-round AI provisions, where the Artists 4 Safe AI letter — as Scott Alexander records — "showed more specific interest in existential risks" from advanced AI and pivoted explicitly away from the sectoral artist-protection frame. The letter's central framing line, captured by Deadline, made the move on its face: "this bill is not about protecting artists — it's about protecting everyone."

The cross-membership is the release's distinctive structural feature inside the campaign. The signatories carried into the Artists 4 Safe AI letter the celebrity legitimacy SAG-AFTRA had built through the 2023 strike round, and applied it to a frontier-AI safety bill whose substantive provisions — third-party safety testing, civil liability, whistleblower protections, the CalCompute public compute cluster — did not concern the signatories' own sectoral interests. The Hollywood public-figure roster lent its mainstream-audience reach to a public-safety case framed in the third person.

Sequencing into the veto

The release sat four days ahead of Governor Newsom's 29 September 2024 veto of SB 1047. Newsom's veto message did not address the Artists 4 Safe AI letter by name, framing the substantive objection around the bill's size-only threshold and its lack of an "empirical trajectory analysis" of frontier-AI capabilities, and pairing the veto with the convocation of the Joint California Policy Working Group on AI Frontier Models under Fei-Fei Li, Mariano-Florentino Cuéllar, and Jennifer Tour Chayes. The letter's substantive provisions — the bill's third-party evaluation, incident-reporting, whistleblower-protection, and risk-disclosure provisions — were carried forward into the working group's final California Report on Frontier AI Policy of 17 June 2025 and into Senator Wiener's successor bill SB 53, the Transparency in Frontier Artificial Intelligence Act, which Newsom signed into law on 29 September 2025 — exactly one year after the SB 1047 veto.

Significance for the corpus

Inside the corpus this Event entry sits as the public-mobilisation peak of the Encode Justice SB 1047 campaign's Hollywood letter track and the corpus's clearest example to date of celebrity legitimacy being routed away from the signatories' own sectoral interests and toward a frontier-AI-safety frame addressed to the wider public. The release matters on three connected counts. First, it is the only major public artefact in the SB 1047 mobilisation in which Hollywood public figures collectively endorsed the bill on broad public-safety grounds rather than on the entertainment-industry deepfake or likeness-protection grounds the 2023 SAG-AFTRA strike round and the parallel creative-industry visual-artist track had organised around. Second, the release's coordinating arrangement — a youth-led civil-society co-sponsor (Encode Justice) organising the Hollywood signatory recruitment under a campaign banner (Artists 4 Safe AI) with a separate call-to-action site (peopleovermachines.org) — is the working template the corpus's later state-AI-policy organising has cited when staging celebrity-signatory letters at state-legislative signing decisions. Third, the release's distinct framing from the union-side SAG-AFTRA letter, despite the substantial signatory overlap, makes the campaign's deliberate two-letter architecture legible: the celebrity-signatory and union-institutional tracks were organised on the public record as separate communications, sharing personnel but addressing different parts of the public-safety case to the same signing decision.