@herrmannpierre
The mechanism is called Schengen Information System (SIS) and any Schengen member can issue bans that all apply Schengen-wide (not EU-wide, as not all EU member states take part in the Schengen area and some Schengen participants aren’t EU members, it’s complicated).
I’d be really curious to see the justification for that entry though. Since Abu Sittah went to Den Haag in Jan 2024, this entry must be very recent. As of now, the incident does not seem to make any waves in German media. It’s mainly a UK/France issue at the moment.