Why Nym is against Chat Control

Chat Control is back, and Brussels has changed the rules to force it through. This week the European Parliament voted to reinstate the "temporary" regime that lets platforms like Meta scan private messages for child sexual abuse material — the same extension MEPs rejected in March, 311 votes to 228. The European People's Party revived it through a rare procedure that flips the math: the law now passes unless at least 361 MEPs actively vote it down. Today they didn't.

The permanent version, the Child Sexual Abuse Regulation (CSAR), grinds on. Its supposedly final trilogue collapsed on 29 June over the Council's demand for suspicionless scanning, and the fight now passes to the Irish presidency. The branding keeps changing — "upload moderation," "detection orders," "voluntary" derogations. The idea does not: software that inspects your private messages before you hit send. Here is why Nym fiercely opposes it.

1. Chat Control is mass surveillance wearing the mask of child protection.

Every version of this zombie makes the same move: take a real horror, the sexual abuse of children, and use it to justify inspecting everyone else's private messages.

The objective is one almost everyone shares. The method — scanning a whole population to find the guilty few — is what surveillance always looks like. EDRi calls this the most criticized draft EU law of all time. Mass surveillance never arrives as surveillance. It arrives as safety.

2. It reads your messages before they're encrypted. That's the whole trick.

Chat Control can't break end-to-end encryption head-on, so it goes around it. Client-side scanning inspects the files on your own device before encryption is applied.

Picture your phone checking every photo and message against a government-supplied list, then reporting matches to the authorities. The message is still "encrypted in transit," that is, after a copy has already been read. Let's just call it a backdoor with better manners.

3. The technology does not work, and Europe's own scientists proved it.

This isn't just Nym's opinion. More than 700 of the world's leading cryptographers say so in an open letter co-authored by Bart Preneel — KU Leuven professor, one of the most cited cryptographers alive, and a Nym advisor. Their verdict: the detection technology is doomed to be ineffective.

Every method fails in its own way. Exact-match hashing catches only unmodified files. Crop or recompress an image and it slips through. Perceptual hashing can be defeated by changes invisible to the eye, or tricked into flagging innocent pictures to bury investigators in noise. Machine-learning detectors are so context-blind they can't tell abuse from a parent's medical photo. The people who build this technology are telling governments, in writing, that it can't do what the law promises.