First, it's not hard to get, if you are (1) close to the target or (2) the NSA or (3) a criminal or (4) hang around some in one of the first three groups.
Second, if people and institutions are tending to rely on this information to make decisions about particular individuals, they are just wrong. They ought not to and if they do they should be incarcerated fined and sued for damages.
Granted all that data can model groups, or insurance companies and many other similar activities just would not work. Useless in dealing with people one at a time, whether on has friendly or hostile intent.
Finally, people evolved and until recently - no more than 12,000 years ago - invariably lived so that all knew everything about everyone they dealt with. That is the normal for homo sapiens. Privacy, anonymity and so on are artifacts of incompetent technology, and seem thought to be of value because commonly said incompetent technology has been unwisely if not maliciously used.
Gossip isn't intrinsically malicious - just an effective way of pressuring people to conform, and the least violent and intrusive such thing so far discovered.