Hossein Yazdi

Both major labs switched on text watermarking within 48 hours at the turn of August. My first thought was that this is very hard to do in a way that actually holds text has no pixel layer to hide anything in. So I read Anthropic's own documentation on how it works.

It does work. It also breaks in a lot of ordinary situations, and they say so themselves: short text leaves too little signal, heavy editing or translation thins it out, screenshots and format conversion strip it entirely.

I audited an AI-written billing service this week. 22 findings, 10 critical.

None of them crashed. All returned 200. Four that stuck with me: an auth check that silently lets anyone in when one env var is missing, SQL injection in the one query that wasn't parameterized, a broken permission boundary so anyone can attach a charge to a workspace that isn't theirs, and a Stripe retry that double-grants seats because there's no idempotency check anywhere.