They track cars, humans, literally everything. Society is one massive database. And the cops are basically given free reign to do whatever they want with that. That could include stalking people they don't like or their exes. In one case a dude got in his car drove for hours to get some legal weed in another state drove all the way home and they showed up to arrest him.

We're headed into a massively dystopian surveillance state where the government and major corporations will be able to monitor, plot, and plan for virtually everything that we do.

Edit: Downvoter: I normally don't care about your type because fuck random internet people, but why do you want a surveillance state? Boggles my fucking mind.

in America whenever you go to a supermarket (grocery) or diy (hardware) store there are giant poles mounted on industrial generators surrounded by lights and signs that track your every move.

They are ALPRs (automatic license plate readers) which have a shared database around the country. Police from cities which have a contract with flock are able to search this database which is across the whole country.