Developer says a hands-free Claude Code session on Opus 5.5 deleted the entire Windows C: drive; 98% recovered from daily backups (first-person, X)
In X posts of 6 and 7 October 2026, a developer writes that Claude Code running Anthropic's Opus 5.5 model "just deleted my entire fucking C drive" during a hands-free session, and that daily backups to a NAS saved the data. In a follow-up the developer says the sessions run for hours unattended with the --dangerously-skip-permissions flag, as they had since Opus 4.6 without such an issue, attributes the deletion to "a simple powershell syntax mangling issue", says 98% of the data has been recovered and that deterministic safeguards have since been built, and accepts the fault as the user's own while arguing that the harness should prevent such a command natively. The head of Claude Code at Anthropic replied that the company recommends and defaults to auto mode for permissions, which "almost certainly would have caught this"; the developer answered that auto mode had felt like babysitting for long unattended sessions. The account is the developer's own. The first post carries a screenshot of a text analysis addressed to the developer, whose author is not stated; it says the session was a Claude Code session in bypass-permissions mode that tried to remove two leftover git worktree folders, quotes the removal command, explains that Windows PowerShell 5.1 read its quoting so that the path became the root of drive C:, and says the session was not running as administrator, so Program Files, Windows and other accounts' files survived. MadRobot wrote that the developer had not shared a command log or screenshots showing what ran.
AI involvement reported · Causal attribution alleged · 4 sources, 2 underlying accounts · Added 10/10/2026