By enabling this option, each time an anonymous user is banned from a chatroom, it's IP will also be banned from the chat server. Warning: if your instance is open to registration, any user could create a trapped-room, invite users to join, and automatically ban all anonymous user's IPs. The banned IP list is not stored, it will be cleared on server restart, or when you change some plugin's settings. The banned IP are logged in the Prosody server log files, so server's administrators can eventually use some external tools (like fail2ban) to ban IPs more widely.
Warning: if your instance is open to registration, any user could create a trapped-room, invite users to join, and automatically ban all anonymous user's IPs.
The banned IP list is not stored, it will be cleared on server restart, or when you change some plugin's settings.
The banned IP are logged in the Prosody server log files, so server's administrators can eventually use some external tools (like fail2ban) to ban IPs more widely.