Very true, I support this, but the law is still needed imho unless we're fine normalizing the continuation of corporations tightening the screws on workers to keep their labor costs within their desired tolerances. It's about control, of course, as it always is. Protect the human from bad actors, broadly speaking.

I would be chuffed if I see someone present on breaking this at Defcon this year.

Most of this will be under 'tracking the corporate asset'. They aren't tracking you as a person, but instead a laptop or phone of which they own or control. That's going to be much harder to defeat in the US.

Invasion of privacy is legal in the US.

Without some sort of organized intervention this sort of tracking will only get worse. A law is the basic way to enforce collective behavior, but sure, if your government doesn't pass one then you should organize some other way. Probably a union in this case.