And it creates problems that just weren't problems when the law was written. Maybe the laws should have been written more carefully but that's a rather idealistic position. That laws regarding control of personal airspace over my house didn't anticipate the widespread use of consumer drones is pretty understandable. Ditto lots of laws regarding regulation of weaponry, etc.
In this case, we've been seeing nominally public info become more readily available for a while now. There are good reasons most public information (deeds, etc.) are public. But that used to mean someone had to have a good reason to look at them because they'd have to trudge down to the county clerk's office. And maybe the town clerk's office. And then some other clerk's office. Now it's all aggregated in one place at the touch of a button. The good reasons those records were public in the first place haven't gone away. But technology has fundamentally changed the scope of how that information can be used.
However, throwing a huge net and catching everybody, then later filtering out what you want is a totally different process. It is leading to a process where guilt is often presumed and you filter out those later who aren't guilty of something. These types of processes continue to reverse innocent until proven guilty to guilty until proven innocent.
In terms of reducing the scale to a single person (which I think has problems, but nonetheless), I don't think most people would classify police following someone around to see what religious ceremonies, political meetings, and protests he or she goes to is acceptable, however we don't worry as profoundly about this because police simply don't have the manpower to do it. License plate readers change this, making mass monitoring of individuals feasible.
Not to mention scale... having a few thousand police officers patrolling a city is acceptable... Having several battalions of a hundred thousand soldiers, not so much.
Do remember, that before this technological advance there was a decided cost to surveil someone. A unit or several would have to be placed on detail to monitor one person. That cost has gone down substantially and as a result, what might have seemed innocuous before has taken on a completely different character. We, as a country, tolerated many injustices towards minority groups because it didn't impact us. Now, we are faced with an impact that is total. It doesn't change the question but does reframe the question.
Yes, this is something the police should be able to do. But that is not the question at hand, is it? This is about performing physical surveillance on all individuals, all the time. Those are two very different things!
The issue here is: is it right for the police to be able to perform physical surveillance of an individual? It's a yes or no question, regardless of what use the police make of technology. If you think the police shouldn't be able to follow you around to see what meetings you go to, which they can do now without a warrant, then it shouldn't matter if they do it with their feet or by automatically capturing and recording license plate numbers.
Technical capability doesn't alter the definition of right and wrong. This is why we should think through laws and rules carefully, so that they apply not only to the present, but to how things might be in the future. If it turns out that we need new laws, then there's a process for changing them. But I don't think that we should let the technical trends of the moment alter how we view our basic principles.