AI and ChatGPT Defamation: When Artificial Intelligence Spreads Falsehoods

Artificial intelligence tools like ChatGPT, Google Gemini, and Microsoft Copilot can generate convincing but entirely false statements about real people and businesses. As AI adoption accelerates, the question of legal liability for AI-generated defamation is becoming one of the most pressing issues in UK reputation law.

How AI Generates Defamatory Content

Large language models (LLMs) like ChatGPT generate text by predicting the most likely next word based on training data. They do not "know" facts — they produce statistically plausible text. This means they can confidently assert entirely false information, a phenomenon known as "hallucination."

AI hallucinations have already caused real-world harm. Chatbots have falsely accused individuals of criminal conduct, fabricated academic misconduct allegations, invented non-existent court cases, and generated false professional histories. Because AI outputs appear authoritative and well-written, users may accept them uncritically and republish them — amplifying the defamatory effect.

Who Is Liable for AI Defamation?

UK defamation law was designed for human publishers, and its application to AI-generated content raises novel questions. Several parties could potentially face liability:

• The AI developer: Companies like OpenAI or Google that create and deploy AI systems may bear responsibility as publishers if their systems generate and display defamatory content.
• The user: Anyone who prompts an AI to generate defamatory content and then publishes it (e.g., posting AI output on social media) is clearly liable as a publisher.
• Websites using AI: Businesses that use AI to generate website content, customer responses, or marketing materials are responsible for the accuracy of that content.
• Intermediaries: Platforms that host AI-generated content may face liability under existing intermediary frameworks.

Applying the Defamation Act 2013

The Defamation Act 2013 requires "serious harm" to reputation. AI-generated defamation can certainly meet this threshold — a ChatGPT response falsely stating that a professional has been struck off, convicted of fraud, or involved in misconduct could cause devastating harm if widely shared.

The Act's defences may present difficulties for AI developers. The truth defence requires the defendant to prove the statement is substantially true — which is impossible for hallucinated content. The honest opinion defence requires a genuine opinion based on stated facts — AI does not form "opinions." The public interest defence requires a reasonable belief that publication was in the public interest — which is difficult to establish for automated outputs.

Practical Steps If AI Has Defamed You

If an AI system has generated false and damaging statements about you, take these immediate steps:

• Screenshot the AI output, including the prompt used and the platform
• Document any republication of the AI-generated content
• Report the issue to the AI provider through their feedback mechanism
• Consider whether the content has been picked up by search engines or social media
• Seek legal advice promptly — the one-year limitation period applies

The Regulatory Landscape

The UK government's AI regulation framework, the Online Safety Act 2023, and evolving case law will shape how AI defamation is treated in coming years. The EU's AI Act may also influence UK practice. While the law is developing, the fundamental principle remains: individuals and businesses have a right to protect their reputations from false statements, regardless of whether those statements were generated by a human or a machine.

Our online defamation solicitors are closely monitoring developments in AI defamation law and can advise on claims arising from AI-generated falsehoods. Contact us for a free case evaluation.

Related reading: Deepfake defamation | Defamation in the digital age | How to remove defamatory content