If you're on company time, you can be fired for anything you do. If it's your phone, outside of company time you can do whatever you want. If it's their phone, it's their rules for their phone all the time.
It's pretty simple, really.
However, one thing I will NOT DO, is ever attach my own phone to an exchange server and allow it to have permission to control literally everything on my phone, from disabling wifi, access to the camera, to forcing a operating system reset. When I first got my phone and that prompt popped up I thought, "You've got to be kidding me. This is real?"