Simon Willison names the lethal trifecta
Named the lethal trifecta — the rule that data theft becomes possible when three things come together in one agent: access to private data, exposure to untrusted content, and the ability to communicate externally
Why it matters
Became the practical checklist of agent security discussions. Vendor documents and security guides adopted the three-part distinction as is
Source — Primary sources first; secondary reports are labelled “Press”
Officialsimonwillison.nethttps://simonwillison.net/2025/Jun/16/the-lethal-trifecta/Added in Week 35, 2026 · See that week