Those are bans being sent to your server from the Hub.
I recommend you go to your account manager, click 'Manage Servers', then uncheck the three 'Accept xxx Bans' flags, and finally, check the 'Enforce Bans' flag.
If you do not do this, you must click 'Master Ban Index' from the PBBans homepage and update your ban list manually (one off update). Checking the 'Enforce Bans' flag means you don't have to do this.