> The internet seems to specialize in this sort of "doxxing". Why? My theory is that the internet, even if you have a real name for a handle, still distances and dehumanizes others to the point where it's hard to understand the pain you're causing.

That's a good theory. My personal theory is there are a lot of psychopaths and sociopaths in the world, and the internet lets them find each other and form communities that revel in causing misery.