There are lots of laws against following someone and observing/recording every move they make.
Making some observations out your window of cars passing by is something no one ever had a problem with. Taking down every single identifier you could and coordinating with others to track that person, for a profit, is something that would not be kosher in meat space.
Why this different just because it's on a computer?
The laws you talk about are, I think, laws about stalking. I'm not aware of any laws that apply to that kind of thing if it happens on a massive scale. Singling someone out is an important part of stalking.
Keeping detailed information about everyone that enters your store isn't illegal, as far as I know. Especially not information that is gained from observation (what color shirt they're wearing, their IP address) and information that is submitted willingly (their name given for a reservation at a restaurant, their username).
Making some observations out your window of cars passing by is something no one ever had a problem with. Taking down every single identifier you could and coordinating with others to track that person, for a profit, is something that would not be kosher in meat space.
Why this different just because it's on a computer?