Generally, using an internal IM client provides a stronger guarantee that all people in the group are employees. This reduces the risk of leaking out sensitive

Generally, using an internal IM client provides a stronger guarantee that all people in the group are employees. This reduces the risk of leaking out sensitive info, or the chances of a journalist/competitor snooping in, or phishing attacks etc. As such, employers should strongly prefer that such communication happens via internal channels. It is the smart thing to do, unless you believe that employees would just stop discussing these things if you banned them from internal IM. But of course, this is Apple.