On average only 3 pieces of information are needed to identify a person. Sure you're person 1234567890, but all the information linked to that user can find out exactly who that person is.
There is a reason phrase like microtargetting exists. When a political group is able to target individuals using their platform, that's not okay.
It gets worse though, government surveillance is one thing, it's another when Corporations give them full access to their data. Or did we forget Snowden already?