The whole expectation of privacy argument is so obtuse.

If I find you in public and start staring at you and following you everywhere without ever going away, including camping out at the door of every private space you enter and exit. You will absolutely have a problem with it. We even have a word for it and laws about it.

The fact that the barista saw you at the coffee shop and your roomate saw you at the library and the book store has an ordinary security camera are nothing remotely equivelant.

One is stalking, even harassment, and the others are not.