This is a data retention/sharing issue, not a technology issue. Nobody cares if their face, license plate or cell phone is seen and mapped to their identity as long as the interaction and its metadata is soon forgotten. It's the storage of this information that causes the problem.

When police can accurately determine who they're looking for based on their appearance and can quickly determine whether the person they're bothering is that person they are more limited in how they can harass people in the present. If no records are kept big brother is more limited in his capacity to harass people in the future.

Most people don't have any warrants out, haven't recently been recorded on a security camera robbing a liquor store, etc. Being able to ID people reliably without stopping them is the last thing law enforcement wants (let's ignore the three letter agencies for a minute here) because it makes it much harder to stop people for being "suspicious" or "looking like a drug dealer" (license plates provide similar protection for cars, they can't just stop every silver Camry because a silver Camry was once stolen).

License plates and cell phones almost map 1:1 to your identity. Nobody has a problem with license plates or phones as long as they're not used to stalk people at scale. It's the creation of the data-set that can be used to stalk people. We need to stop creating these data sets in order to prevent the stalking at scale (which is the real issue here, even the article says that).

Imagine a world where the speed limits were followed like normal laws (i.e. they were reasonable enough that most people didn't have to go out of their way to follow them). The police in that world would hate radar guns because they're accurate (and can be audited for accuracy) Big brother would hate them because they don't record metadata for each reading. Facial recognition, ALPRs, need to work like that. History has proven time and again that you can't keep technology in the closet. Better it be used on our terms than theirs.

We're going to have to confront the data retention and government/commercial stalking/surveillance issue eventually. Getting angry over APLRs, stingrays or facial recognition is just playing whack-a-mole. I'm still gonna play whack-a-mole until we solve the big problem though.

Edit: If people disagree I'd love to hear why. This isn't Reddit.