A public ban list maybe good, but this may invade the privacy of those who banned (because they may use the same name at other sites). If this is made, I suggest only to include who were perma-banned, but not for those who banned for 7/30 days.
It already exists a list (not 'functional' at all) here :
https://bitcointalk.org/modlog.php for example :
Nuke user: N/A in topic #0 by member #517541
Nuke user: N/A in topic #0 by member #517542
Nuke user: N/A in topic #0 by member #517543
Nuke user: N/A in topic #0 by member #517544
Nuke user: N/A in topic #0 by member #517527
Nuke user: N/A in topic #0 by member #517528
Nuke user: N/A in topic #0 by member #517526
Nuke user: N/A in topic #0 by member #517521
Nuke user: N/A in topic #0 by member #517540
Nuke user: N/A in topic #0 by member #517562
Nuke user: N/A in topic #0 by member #517563
Nuke user: N/A in topic #0 by member #517564
Nuke user: N/A in topic #0 by member #517565
Nuke user: N/A in topic #0 by member #517566
or
Autoban user: N/A in topic #0 by member #516470
Autoban user: N/A in topic #0 by member #516820
Autoban user: N/A in topic #0 by member #516818
Autoban user: N/A in topic #0 by member #515014
Autoban user: N/A in topic #0 by member #513982