Anthropic tightens Claude's system prompt against reproducing song lyrics after Sony Music Publishing, Warner Chappell lawsuits
2026-09-02
Simon Willison reported on September 2, 2026 that Anthropic's published system prompt for Claude Fable 5.1 added a substantial new section instructing Claude not to reproduce song lyrics, poems, or book/article passages — including choruses or paraphrased lines — and to keep declining reworded requests for the rest of a conversation; a parallel new section forbids generating images of copyrighted characters, logos, or artwork. Willison notes this closely follows news that Sony Music Publishing and Warner Chappell are suing Anthropic over training on databases of song lyrics, though he does not cite a primary source for the lawsuit itself.
Significance 3: A concrete product-behavior change tied to active copyright litigation against a tracked lab is a real governance/legal development; held at 3 because the only source in this run is a single curator post without a primary or press source confirming the lawsuit's filing details.
Implications · machine-drafted, not owner judgment
This is a documented instance of a lab changing model behavior reactively in response to litigation rather than proactively — echoing the already-evidenced Meta pattern of shelving its own research on hiding like counts until legally forced to default it. It suggests copyright litigation, not internal policy design, is currently the more effective lever constraining what frontier chat models will output, which matters for how much weight to put on any lab's stated content-safety commitments.
- Primary reporting or court filing details on the Sony Music Publishing / Warner Chappell suit against Anthropic
- Whether other labs adopt similar lyric-reproduction restrictions around the same time
- Any settlement or ruling in the case
Sources
- curator Claude's new system prompt really doesn't want to reproduce song lyrics retrieved 2026-09-02