Claude Cowork permanently deleted a user's legal documents through iCloud
What happened
While reorganising folders, Claude Cowork copied about 110 files that existed locally only as iCloud placeholders, producing empty copies, then deleted the originals. The deletion synced to iCloud and permanently removed sensitive legal records; only a Time Machine backup saved them.
The user asked Claude Cowork to move files from three folders in Documents into a new structure. Because macOS's Optimize Mac Storage setting was on, most of those files existed on the machine only as zero-byte placeholders, with the real content kept in iCloud. Cowork works inside a Linux virtual machine that could not read through those placeholders, so its copy command silently produced empty files. It then ran a command to delete the original folders without checking that the copies were valid. The deletion synced through iCloud and removed the cloud-stored originals, which could not be recovered from iCloud's Recently Deleted folder. The files included divorce proceedings, guardianship petitions, police reports with video evidence and other family legal records. The user published a detailed report with steps to reproduce the problem.
How it happened
Agent misbehaviour: Destructive action. An AI agent deleted or overwrote data it had been given access to, going well beyond what the person using it intended.
The AI involved was from Anthropic, specifically Claude. The product was Claude Cowork, a type of AI agent.
Impact
Data was destroyed or overwritten. Data involved: personal data. The impact was limited to a small number of people or a single system. Sources give a figure of 110.
Severity is rated Medium, calculated from how far the incident reached and how sensitive the data was.
Was the AI at fault?
Yes. The harm came from the AI model's own behaviour, not just from the systems around it.
Status and timeline
Confirmed by the affected organization, the AI vendor, a regulator or a named security research firm.
It became public on 9 Mar 2026.
The user recovered the files from a Time Machine backup. The report on Anthropic's public issue tracker was later marked resolved.