Enjoy anonymity.
It does not surprise me much, seriously.
I have seen before people who are part of webpages and groups which try to track down other users in the internet and dox them, for the sake of entertainment/amusement. I recall a case when one of those victims of doxxing had to change their names and move to a different State within the United States of America, in order to escape the continuous attempts to unveil their identities and personal information again.
In the end, the group of doxxers managed to get new names and new address of those people in less than three months of research.
I do not know how they were able to pull off something like that. It would seem that on the internet there is certainly people with special skills to search and connect information, which otherwise would mean nothing to an untrained eye.