As an Admin, I want the ability to restrict or disable use of the "@all" alias in HipChat Server

Problem

There currently doesn't seem to be any way to disable or restrict the use of the @all alias in HipChat Server.

An example of the need for this request from a customer:

"Several times a week we are party to a discussion on some channel about proper use of the "here" and "all" aliases on HipChat. The former is acceptable. The latter almost never is except in an earthquake, fire, tornado, etc. since it notifies everyone with an account.
This impacts the entire company and is a huge distraction. The accumulated context switches across the company because of this simple issue must be enormous."

Suggestion

Provide an easy way, possibly via a HipChat Server Preference setting, to either restrict the use of the "@all" alias to Administrators only or maybe even disable its use altogether.