I work as a security guard and my company has a no cell phone policy at work. It is quite dreadful since I work at a post where nothing is going on and I just do a patrol every 2 hours and let people in through the gate. Like I understand that some places demand your full attention for 8 hours and you should be busy and I get that. But for places where not much is going on that sucks. I personally ignore the no cell phone rule and use my devices anyway since I rarely see my supervisor maybe once every two weeks or once a week. But I would rather see my guard doing something and being occupied than falling asleep.