I pay for the service for my company. I trust my employees. I don't want them to think I'm snooping on their personal conversations between each other.
You also control the routers, the email server, any other form of digital communications, and possibly even the software in their desktop.
What's the difference? Just because an employer can snoop -- and might be legally obligated to snoop -- doesn't mean your company can't have a clear policy regarding when and how you will exercise that ability inherent in owning infrastructure.
Well most of the team is remote and we use Google Apps which doesn't allow email access (as far as I can tell, at least not without changing passwords and a few other tricks).
There is a difference between having a feature which allows someone to view your private chat logs (something Google Apps doesn't have) and what it sounds like HipChat are implementing - though maybe they're going to make it just as difficult?
