Up to a point, we can be anybody we want to be on social media. Sure, we might have the ever present threat of doxxing looming over our heads, but with enough canny characterization you can still live out your wildest alternative life.
However, this is not the choice of most people, who instead decide to be themselves up to a fault. While they might distance themselves with certain things, they can't help spilling the beans on minute details of their life — even when they probably shouldn't. To misquote an iconic cartoon rabbit: do you really think someone would do that, just go on the internet and give away far too much information? Yes, yes they would.