After said research, my current impression is that since secret alliances cannot be proven (unlike multis), that no action will taken against them by the admins. Example: One thread I looked at posted the PM where a player suggested a secret alliance (could have been made up, I know). The suggestion that was offered was to use the ignore and negative feedback.

Sorry if this has been discussed before - I didn't find it. Thanks for any responses I get.
Edited to add: Also sorry if this is the wrong Forum since it's not an actual report, yet.