Broadcast Message

Sometimes as an admin I need to broadcast to our team outages and such. I'd like the ability as an admin to send a message as a console message that cannot be replied to.

Bare minimum would be to at least assign an admin flag to a user that is able to use this ability. I know potentially it could open a lot of windows. So maybe there is a way to broadcast without opening the windows. But there really needs to be a feature to send messages like this to only all "Online" people.