Certainly for some people. But for many who are on the web professionally, it can be hard to separate professional and personal identities. And especially once people are public in other ways, such as by owning homes and, at least until recently (sometimes) having a landline, it doesn't take a private investigator to link some facts about someone to a great deal of information--at least some of which is often public by law.

A great deal of the mainstream Internet was not anonymous/pseudonymous.