
AI data training startup Mercor admitted March 31 to a data breach exposing 4TB of information including candidate profiles, employer data, and source code. A hacker group claimed responsibility. Meta paused contracts indefinitely; OpenAI investigated but continued working. Five contractors filed lawsuits. The breach resulted from compromised open-source tool LiteLLM. Mercor was valued at $10 billion after raising $350 million in Series C funding.