>https://www.roadtovr.com/facebook-horizon-privacy-monitoring-moderation/
>Second, anyone you interact with can invite an invisible observer from Facebook to come surveil you and your conversations in real-time to make sure you don’t break any rules. The company says this can happen when one user reports another or when other “signals” are detected, such as several players blocking or muting each other in quick succession. Users will not be notified when they’re being watched.

Damn, lucky I have an Index.