There is situations and formats that might need the participants to interact with the chat or having someone hosting the chat as a mod.
Once you logged in to the backend, open another tab/browser window with the separate chat (use the links shown in the beginning of this page!).
As you hover over the messages now, you will now also see extended options to delete messages or ban users.
(ATTENTION: You need to be logged into the backend first, before these options appear!)