Would humanity be better off? Or are people stupider when they are thinking out loud in front of recording devices?
How much do the lawyers deserve to know?
Nothing IMO. They can look at the company's actions. There's no need to invade the privacy of individual employees.
If they were trying to confiscate my personal mobile that I use for work I will never go along with that.
Luckily I live in Europe where the atmosphere is far less litigious.
That is a good reason never to use your personal mobile for work! If you really need a phone to do your job, your employer should be paying for it anyway.
People look at me like I have two heads when I tell them that my work devices are for work things and personal devices are for personal things.
There are very rare exceptions to this rule.