My company provides me a cell phone so that I can receive text messages from our computer systems for any errors or abnormalities. My job is to ensure that my jobs don't do bad things and bring our systems down. If I don't do this part of my job, I won't get anywhere career wise, and I'll definately be out of a job. This is the price of a "salary" job.

Not all of us have the opportunity to just "turn it off". Yes, you can have someone cover for you, but not everyone has that option.