I don't think you get it.
It will NEVER be illegal. They will NEVER outlaw data collection. Law enforcement wants it. Big business wants it. They both want it for different reasons...but they want it.
The Fourth basically only applies within the walls of your own home...and not even then in some cases. If it can be seen from public...then it's not protected. This includes your yard, your street, inside any open windows....anything.
The minute you leave your house...your cell phone is reporting where it is just for basic network functionality....which can be handed over to police with a warrant...or they can just buy the data like they usually do. No warrant required...it's below budget thresholds.
If you think privacy protections are coming; you're wrong. The only thing we've gotten is less privacy. NEw cars have to spy on you. They're probably going to spy on everything. Who needs a flock network when you have a federally mandated network of sensors in cars you can use.
They will never restrict this data by law and you're foolish if you think anyone is.
The politicans don't care about us. Both sides support this...therefore it CANNOT be good.