Ben Horowitz calls Anthropic 'one of the most negligent companies' on security, says its reply to a hacked test site was 'you prompted it wrong'

Andreessen Horowitz co-founder Ben Horowitz said on the All-In podcast that Anthropic is "one of the most negligent companies that we've ever seen in terms of security."

In a clip the show posted to X on Oct 17, Horowitz said the firm ran cybersecurity checks when it first got Claude Opus 4.5. One agent built a website for a pet store; a second agent was told to find exploits in it. Asked whether a SQL injection it had found was really exploitable, the agent answered "Let's pop it open," broke into the site and stole all the customer data, he said. "We then call Anthropic, and what they tell us is, 'You prompted it wrong.' Like that was their answer." The clip passed 1,100 likes and 110,000 views.

Anthropic has not responded publicly. Replies pointed out that Opus 4.5 is about a year old and that Opus 5.5 would be a fairer test; one joked that an agent writing the SQL injection and another exploiting it makes "a full-stack team."