Several large companies have restricted or stopped using Anthropic's flagship models following a change in the company's data retention policy. The immediate cause was the June 9 release of Fable 5, which introduced a mandatory 30-day retention for Mythos-tier models, overriding previously signed irrevocable zero-data-retention (ZDR) agreements and offering no opt-out.
What the partners did
- Nvidia moved proprietary supply-chain work to its own Nemotron system.
- Palantir stated it will not ship Anthropic models to customers unless Anthropic provides an irrevocable zero-data-retention pledge.
- Booz Allen Hamilton banned the use of Anthropic models for client cybersecurity work.
Timeline and trigger
The policy change took effect with the Fable 5 rollout on June 9, when Anthropic applied a mandatory 30-day logging and data retention rule to Mythos-tier models. According to reports, this rule superseded earlier ZDR agreements that had been signed and did not allow an opt-out.
Why this matters
The issue has both business and security implications. Corporate customers frequently process sensitive supply-chain and operational data and rely on strict contractual guarantees about data handling. The current responses signal that some partners are unwilling to work with a provider that does not meet their required data-management terms.
Consequences and outlook
In the short term, Anthropic may lose business or access to strategic customers. Over time, the dispute could prompt broader discussion in the industry about standardizing practices and contractual guarantees for data handling with large models. For now, several major clients have limited or blocked the use of Anthropic's models pending changes to its data-retention policy or new contractual assurances.
