Audience: Senior security engineers and DevOps leads evaluating PII infrastructure for AI-connected systems. Three events in the past eight weeks drew a line around a specific class of infrastructure risk. Taken together, they validate a thesis we have been operating on since day one: PII that leaves your trust boundary is a liability, and any system that lets it do so — intentionally or not — is a breach waiting to happen. Event 1: The supply chain vector (March 2026) A prominent AI startup suffered a breach through an open-source pipeline tool positioned between their internal data stores and an external AI provider. The attacker did not compromise the AI provider, the data store, or the application layer. They compromised the connector. 40,000+ PII records exfiltrated. The entry point was a third-party tool doing exactly what it was designed to do: passing data along. This is the attack surface specific to AI adoption — the middleware.…