Follow politics close enough, each step the police gets better technology and so what used to be ok, like the police beeing able to follow a suspect ends up meaning that they can slap a cheap GPS tracker on any car, all without a warrent.

Of course it is admissible evidence when the police see you sell heroin on the street, it is a little different when that gets changed intro a drone that can watch entire neighborhoods from the air.

And when the police gets those rights, so will other people.