It's mostly worthless but the recursive search via aliases can give some interesting insights. I ran it on my GitHub username and while the result ended up link

It's mostly worthless but the recursive search via aliases can give some interesting insights. I ran it on my GitHub username and while the result ended up linking me to countries I have never been to (probably via a yandex account as the username is very common and a lot of the profiles were of other people) it did include my full name and cities I've lived in. It seems the most "dangerous" link in my case was Gravatar. Interestingly, searching by e-mail gave the most garbage results, likely because most services don't expose the e-mail address directly. I guess it's an advantage that neither my usernames nor my legal name are particularly unique.