Reddit Sues Anthropic Over Alleged Unauthorized AI Training Scraping

On June 4, 2025, Reddit, Inc. filed suit against Anthropic, PBC in California Superior Court in San Francisco (Case No. CGC-25-625892), where both companies are based. Notably, the complaint was grounded in contract and state-law business and privacy theories rather than copyright, bringing causes of action for breach of contract, unjust enrichment, trespass to chattels, tortious interference, and unfair competition under California's Unfair Competition Law (Cal. Bus. & Prof. Code section 17200). Reddit said the aim of the suit was to seek damages and compel Anthropic to abide by its contractual and legal obligations, and it asked for a jury trial.

The complaint was unusually combative, opening by calling Anthropic a "late-blooming" AI company that "bills itself as the white knight of the AI industry" and adding, "It is anything but." It alleged that Anthropic "does not care about Reddit's rules or users" and believed it was "entitled to take whatever content it wants." Reddit alleged that Anthropic used automated bots, including ClaudeBot, to train Claude on Reddit posts and comments without a license and without user consent, in violation of Reddit's user agreement, and it quoted Claude itself admitting it was "trained on at least some Reddit data" while unable to say whether deleted content had been removed. The filing also cited a 2021 paper co-authored by Anthropic chief executive Dario Amodei in which company researchers identified the subreddits containing the highest quality AI training data, such as forums on gardening, history, relationship advice and shower thoughts.

A central factual allegation was that Anthropic publicly assured in July 2024 that it had blocked its bots from crawling Reddit, yet its bots accessed or attempted to access the platform more than 100,000 times afterward, and that this activity disregarded Reddit's robots.txt and access restrictions. "Anthropic refuses to respect Reddit's guardrails and enter into a license agreement," the complaint said, contrasting it with Google and OpenAI, which pay to train on the public commentary of Reddit's more than 100 million daily users under licensing terms Reddit says include user-privacy protections.

Anthropic rejected the claims outright: "We disagree with Reddit's claims and will defend ourselves vigorously," a spokesperson said. The company, formed by former OpenAI executives in 2021 and whose backers include Amazon and Google parent Alphabet, had told the U.S. Copyright Office in 2023 that the way Claude was trained "qualifies as a quintessentially lawful use of materials," and it was already defending a suit by major music publishers over song lyrics. It had been valued at $61.5 billion in a March 2025 funding round.

Reddit, which held its IPO in 2024 and carried a market capitalization of about $22 billion, saw its shares close up more than 6% on the day of the filing; OpenAI chief executive Sam Altman, whose company is a licensed partner, is a former Reddit board member and one of its biggest shareholders.

Anthropic removed the case to the U.S. District Court for the Northern District of California (Case No. 3:25-cv-05643), where it was assigned to Judge Trina Thompson. A key threshold dispute was whether Reddit's state-law claims were preempted by federal copyright law — which would keep the case in federal court — or whether they were genuinely distinct contract and tort claims that belonged in state court. The court signed its order on 28 March 2026, entered on the docket on 30 March 2026, holding that the claims were not preempted by the Copyright Act and remanding the case back to San Francisco Superior Court. The remand decision was a procedural ruling about the proper forum, not a determination of liability, and Reddit's allegations about the scale and nature of the scraping remained allegations.

Following the remand, Anthropic filed a demurrer in the state-court case arguing that Reddit's claims were nonetheless preempted by federal copyright law. Per MLex's Amy Miller (13 August 2026), Anthropic told the court the dispute was 'really a copyright fight in disguise' that should be preempted, while Reddit countered that Anthropic had violated 'the platform's privacy policies and other obligations governing how user data could be used.' The demurrer was argued on 12 August 2026. Per Bloomberg Law's Annelise Levy, the judge hearing the arguments 'repeatedly expressed doubt about Anthropic's arguments against Reddit's privacy claims,' though MLex reported that the judge 'gave no indication how he would rule.' In mid-September 2026 (reports date the order between September 17 and 19), San Francisco Superior Court Judge Harold Kahn ruled on the demurrer. Mashable reported that the order was dated September 17 and filed the following day, and the National Law Review referred to a September 19, 2026 ruling. According to Mashable, Judge Kahn overruled Anthropic's demurrer as to Reddit's breach of contract, interference with contract and unfair-competition claims, which were allowed to move forward, while the unjust enrichment and trespass to chattels claims were dismissed with a chance for Reddit to refile. Mealey's, in a report dated October 6, 2026, likewise said that three claims, including the unfair-competition claim, survived and that the judge allowed Reddit to amend its complaint to cure defects in the unjust enrichment and trespass to chattels claims. The ruling addressed whether the pleadings stated claims, not whether Anthropic was liable: the case remained pending, and Reddit's allegations about the scale and nature of the scraping, like Anthropic's denial of them, remained untested.