Two Is a Crowd Please!
Some people may be protective of their names, despite how strange they may sound. Clearly, this person is a part of that group that feels exclusive with their name. They approached this social media user after seeing that they were using the same name as theirs. So, they needed to find out what exactly was going on.
But as you probably have figured, it’s merely a coincidence and nothing more. Therefore, they would just have to accept the reality that they are not one in a billion. That is unless they had their name on their birth certificate legally altered to something more unique.