A mental-health startup ran GPT-3 on thousands of unwitting help-seekers

The startup Koko used GPT-3 to co-write responses to roughly 4,000 people seeking peer mental-health support without clearly informing them they were receiving AI-generated messages, drawing an ethics backlash over consent in a vulnerable-population setting.

Koko · Incident Jan 6, 2023 · Indexed Jun 3, 2026 · 1 source

Roughly 4,000 people seeking mental-health support received AI-generated messages without clear consent.
What
The startup Koko used GPT-3 to co-write responses to roughly 4,000 people seeking peer mental-health support without clearly informing them they were receiving AI-generated messages, drawing an ethics backlash over consent in a vulnerable-population setting.
Incident date
Jan 6, 2023
Who
Koko
Failure mode
Policy Violation
AI surface
Chatbot
Severity
Medium

What happened

In early 2023 Koko's co-founder disclosed that the service had used GPT-3 to help generate supportive messages to about 4,000 people seeking mental-health support, without clear, informed consent that AI was involved. Ethicists criticized the lack of consent and oversight for an experiment on a vulnerable population, and Koko said it had stopped.

What broke inside the model

Failure path · mode profile · Policy Violation
  1. 01 · TriggerA prompt pushes against a deployment boundary.
  2. 02 · Model stepThe model produces the disallowed output.
  3. 03 · Control gapNo enforcement blocks it at generation time.
  4. 04 · FailureThe output crosses the policy line.
  5. 05 · ConsequenceA limit the business set is breached in public.

The output crosses a policy boundary the deployment had defined.

The system produced an output or action that broke a stated policy or a regulation that applied to the deployment. The model optimized for a plausible response, not for the constraint, and no enforcement layer checked the output before it took effect.

Public visibilityMedium
Regulatory exposurePossible
Customer impactMany customers
Financial impactUnknown
Time to disclosureDays

Ethics backlash; experiment halted

  1. PressStartup uses AI chatbot to provide mental health counseling, then realizes it feels weird (The Verge)theverge.com
Permalinkhttps://failureindex.ai/failures/mental-health-startup-ran-gpt-3
CitationAI Failure Index. "A mental-health startup ran GPT-3 on thousands of unwitting help-seekers" (FI-0077). Realm Labs. https://failureindex.ai/failures/mental-health-startup-ran-gpt-3 (indexed Jun 3, 2026).
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Data fields CC-BY 4.0, prose citation permitted. Incident ID FI-0077. Full dataset at /data.

Note from Realm Labs, the Index steward

How Realm would have caught this

Controls for this failure mode
  • Prism
  • OmniGuard

Realm compares what the model is about to output or do against the governing policy in real time, and can deny or redact the action before it takes effect.