Another post about employers and personal phones reminded me of this.
My husband worked for a particular trucking company for less than a year. Although it was not the worst job he ever had, they were definitely testing the boundaries on what they could get away with. Their turnover rate was insane, but we had just moved to the area and it was the first job he could get. About 1 month into being there, they decided that since drivers like to talk on the phone while driving, they had to intervene because of “safety.” Whether this is legit excuse or not is irrelevant because their solution was to buy an app that forces the phone into airplane mode when it is near the receiver placed in the truck. They forced the employees with threat of termination to have them install the app on their personal phones. This app was designed so only their IT person could remove it (easily). Now, we knew that this was at the very least unethical, but no one was hiring daytime truckers in the area, so we just allowed it.
What they didn't know though, is that my husband is not an idiot and knows how phones and apps worked. A week later, he sat down and found the work around to delete the app without IT authorization or notification. He continued working there for about 5 more months until better a opportunity arose. We did end up getting some settlement money when the inevitable lawsuit occurred.