The right to disconnect
This stuff really gets to me also, and I'm a young(ish) person who is quite addicted to my phone and social media - but not for work purposes outside my 40ish hours a week.
Very much agree with Stacey - if an employer expects a staff member to be contactable 24/7, this needs to be made part of the job description and compensation would need to match.
My father-in-law is in his early 60s working for a large car dealership and he is expected to be contactable 24/7 and reply to ALL emails with a 15 minute time frame... that is insane!
It will be interesting to see how the relatively new law in France around disconnecting from work plays out and if it has any real effect.
For those who have no idea what I am on about: http://fortune.com/2017/01/01/french-right-to-disconnect-law/