I have my doubts about how effective Scarlet A is.
In theory it makes some sense. People will see that another didn’t get away with doing something, so they’ll know better than to try it themselves.
In practice public discipline has mixed results. eg.
PHP-hater and Ruby-hater get into a discussion. What starts off well gets hot fast. Eventually one crosses the line and makes a personal attack on the other.
Staff edits out the HATE and asks them to please tone it down.
Sometimes they do, great!
Other times they’ll scream “censorship”, “freedom of speech”, "the world needs to know that someone on the internet was wrong"
And the public “message” will fail to get across to everyone, count on it.
I imagine pinning a big “this member is a Troll” on a member’s Profile would likewise cause varied reactions and prove to be just as ineffective.
On the other hand, for Moderators keeping a history on a member could be a good thing. eg.
the Staff Notes plugin where “this guy has been given 5 chances already. If he does it again give him a week off” note could save some grief.
It is possible for the Admin to do some witch hunting if they wanted to by querying the muted_users table to get an idea of how others feel.