It is a task given to moderators that whenever they see someone violating the rules listed in the CHATRULES, they have to mute them, not just to give disciplinary action but to remove the chats that are considered a violation to maintain cleanliness and order.
A moderator once told me too, it is the only move they can do to remove the chat from the message board so others will no longer see the violation made and do the same mistake. It is to mute the violator. Besides, the Chatrules are already available at the upper side of the chatroom we just have to click it, take time to read and understand then follow and we are safe from the punishment.