Context is vague. So it's hard to tell.
Yet I do understand the part about
we don't find traces of them on social media now
I have searched for many on other sites, and only found one. And not exactly someone I knew very well.
Actually she recognized me on a junior high Facebook page. That was years ago. I no longer have a FB account. So even if she wanted to contact me it's no longer possible. This obscure site is the only site I'm on.