Anthropic Downloaded Music From Torrent Sites to Train Claude

Sony Music Publishing and Warner Chappell Music sued Anthropic on Friday. They say the company used BitTorrent to take songbooks, then fed them to Claude.

While Anthropic has already admitted torrenting books, it has never conceded that music sat inside those files, hence the copyright case.

Anthropic Music Lawsuit Explained

The complaint names two hauls, both from shadow libraries and containing unlicensed copies of published works.

• Roughly 5 million books came from Library Genesis in June 2021.
• Another 2 million came from Pirate Library Mirror in July 2022.

According to the publishers, sheet music and songbooks sat in those collections. Torrenting is not the only route in the filing.

The publishers also say Anthropic scraped lyrics from Musixmatch and LyricFind. Both sites pay for the right to display them.

“…one of the largest and most blatant ongoing thefts of intellectual property in history,” the opening line of the complaint reads.

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Why Torrenting Is the Dangerous Part

A judge has already drawn this line once. Buying books and scanning them leaned toward fair use. Taking them from pirate sites did not. The same judge described those downloads bluntly.

“…straightforward piracy but at massive scale.”

That is why Anthropic’s destructive book scanning program survived court, while its downloads ended in a settlement.

Torrenting sits on the wrong side of that line, and it carries a second problem. The software uploads while it downloads. Every copy taken is also a copy shared.

Two of the four counts rest on that point, with both naming Dario Amodei and Benjamin Mann as individuals, not as employees. Companies settle. People give depositions.

What It Could Cost

The publishers want up to $150,000 for each song a jury finds was knowingly infringed. The publishers say hundreds of their songs sat in those files. They put the wider training claim in the tens of thousands.

Notably, however, Anthropic has beaten these publishers before. It beat their bid to block Claude’s training in a 2023 case over lyrics. It agreed to run output guardrails instead.

It has not commented on this one.

Everything now turns on discovery. Did the songs reach Claude through a purchase, or through a swarm?