Sorry, I was ambiguous in what I meant.

It is not realistic to say that no person is allowed to keep track of another person; watch where they go, when, with who, etc.

It should not be acceptable for a company to gather information on "everyone"; where they have been going, when, with who, how often, etc. And it should not be acceptable for them to sell that information (to government agencies OR private citizens).

It's a matter of scale.

- Making the first one illegal/impossible would be difficult/costly; and not doing so has a limited impact (to society, not to the single person affected).

- Making the second one illegal is much easier, and it's much easier to shut down a large company doing it than it is 1,000 individual stalkers. The impact of making it illegal is much wider and better for society as a whole.

We don't want anyone being stalked. But in a cost/benefit analysis, we can do something about one of them but not the other.