I've known we've experienced issues with players being banned/muted and using dynmap to circumvent the punishment - but I believe there is an option in dynmap that applies whatever punishment made on the server to dynmap chat as well.
I noticed this when I had banned someone on my server and dynmap had blocked them from speaking on dynmap all together. I believe this is done by configuring dynmap to use the same ip-address as the player to "log in" onto dynmap.
aye that would make sense. I remember when I used it for your server and was wondering why I didn't have to login
I think Frooby messed with it earlier, saw someone speaking as their IP instead of their IGN. Haha