Risk · R-151 · Intellectual Property & Legal Liability
Defamation by AI output
A system publishes a false statement about an identifiable person or organisation that damages their reputation.
- Severity
- High
- Audience
- Heads-of · Practitioner
- Frameworks
- Confabulation · LLM07 · Article 5
- Responsible AI domain
- Lifecycle stage
- Reviewed
- 2026-11-11
What it is
A generative model asked about a named individual or company may invent a crime, a scandal, a bankruptcy or a regulatory finding, or attach a real one to the wrong person. If the statement is communicated to someone else and causes or is likely to cause serious harm to reputation, it may be defamatory. The organisation whose system made the statement, or which republished it in a report, an article or a customer reply, is the natural defendant. That the words came from a model is unlikely to be an answer. The data protection side is covered in inaccurate personal data in outputs.
How it happens
- A public assistant answers questions about named people from the model's memory.
- Generated research or due diligence reports are sent to others unchecked.
- An automated news or summary feature misattributes an allegation.
- People with the same name are merged.
Why it matters
Defamation claims are costly, slow and public. The harm to the person is real and may be hard to undo once a statement has spread. A system that has made one such statement about a person is liable to make it again.
Warning signs
- The system will discuss named private individuals with no source.
- Generated content about people or companies is published without review.
- No procedure exists for a complaint that an output is false and damaging.
- Statements complained of cannot be traced or suppressed.
Who owns it
The owner of the publication or channel is accountable. Legal sets the review standard and handles complaints. Engineering restricts what the system will say about named persons.
In practice
A local news site uses a model to summarise court lists. It reports that a named shopkeeper was convicted of fraud. The conviction was of a different person with the same name in another town. The same pattern generalises to any automated statement about real people that reaches an audience unchecked.
Mitigating controls
Primary controls
- Factuality and hallucination verification Detective
- Checks statements about identifiable people and organisations before publication. Claims, figures and citations in AI-generated output are checked against a trusted source before the output is relied on for a consequential decision or sent to a customer.
Supporting controls
- Feedback and complaints channel for AI Detective
- Gives a route to report and remove a defamatory statement. Users and affected people can report a problem with an AI system easily, and reports are triaged, linked to the system concerned and analysed for patterns.
- Human-in-the-loop review Preventive
- Human review of content that will be published. Consequential AI outputs and decisions are reviewed by a competent person, with the time, information and authority to change them, before they take effect.
- Retrieval grounding and citation Preventive
- Limits statements to sourced material. The system answers only from retrieved, approved sources, cites the source for each statement, and declines where the sources do not support an answer.
Framework and clause references
| Framework | Clause | Title |
|---|---|---|
| NIST Generative AI Profile (NIST AI 600-1) | Confabulation | Confabulation False statements about real people. |
| OWASP Top 10 for LLM Applications | LLM07 | Misinformation Misinformation. |
| UK General Data Protection Regulation | Article 5 | Principles relating to processing of personal data Accuracy of personal data. |
Sources
- NIST Generative AI Profile NIST · framework
- OWASP Top 10 for LLM Applications OWASP GenAI Security Project · framework
Related terms
How to cite
Axiom Verity (2026). Defamation by AI output. Reference Library, R-151. https://axiom-verity.com/risks/defamation-by-ai-output. Reviewed 2026-11-11.
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