No source states: money lost or records count, agent tool, could do, deployer.
Severity minor: One user's files were deleted and later recovered via Dropbox; no third party is reported touched.
A University of Chicago law professor had Claude AI accidentally delete an entire year of Constitutional Law lecture notes and his entire current syllabus.
What happened
1 · What it was doingProfessor William Baude asked Claude to update the page numbers in an old set of lecture notes.
2 · What went wrongClaude deleted Baude's Fall 2026 final syllabus and all top-level Class N 2023 notes by accident, and did not restore them.
3 · What it reached or didThe deletion hit Baude's entire current syllabus and an entire year of Constitutional Law lecture notes.
4 · How it was caughtBaude found out on returning from lunch, when he found a note from Claude admitting the deletion.
What was done
The files were later recovered via Dropbox, and Baude shared the story as a public service announcement.
No source states: when it was found, how many records were exposed, the direct loss, a count of the other parties affected, any court case, the cause, what set it off.
Show every field, with its source and grade
The AI system
Model
Claude
C one secondary source states it
Developer
Anthropic
D inferred by us from the described behaviour, reason shown
Whose system
company using AI
D inferred by us from the described behaviour, reason shown
What it was for
Updating page numbers in an old set of lecture notes
C one secondary source states it
What happened
Earliest source we hold
2026-11-06
D inferred by us from the described behaviour, reason shown
Who caught it
the victim
D inferred by us from the described behaviour, reason shown
Themes
accidental deletion, backup recovery
D inferred by us from the described behaviour, reason shown
Who caused it
the AI system itself
D inferred by us from the described behaviour, reason shown
What went wrong
operational mistake
D inferred by us from the described behaviour, reason shown
AI agent
an AI agent acted
D inferred by us from the described behaviour, reason shown
Impact
Severity
minor
D inferred by us from the described behaviour, reason shown
Who was affected
William Baude's current syllabus and a year of Constitutional Law lecture notes
C one secondary source states it
Why this severity
One user's files were deleted and later recovered via Dropbox; no third party is reported touched.
D inferred by us from the described behaviour, reason shown
Context
Industry
Educational Services
D inferred by us from the described behaviour, reason shown
Notes on gaps
Date of occurrence is not stated.
LR-2026-0853 · version 2 · published 2026-11-06 after automatic checks; not yet checked field by field by a person · changes to this case · JSON
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