“I found sometimes, that it is of great help in handling such a case, to encourage them, to express their peculiar contents either in the form of writing or of drawing and painting. There are so many incomprehensible intuitions in such cases, phantasy fragments that rise from the unconscious, for which there is almost no suitable language. I let my patients find their own symbolic expressions, their “mythology.”
― C.G. Jung, The Red Book

My take on it is it would be worse if they didn't have the internet to express those thoughts, because maybe if they express them they can analize them better and come to the conclusion that certain thoughts are not healthy, much less acting on them. At the very least they vent, and maybe make the rest of us aware that we can't expect the same reactions from them than from other people.

One thing is to fantasize you could run as fast as one of your favourite animals, something else is to meet people who have taken the route to demand recognition as their favourite fantasy and seeing the effects of that on the people you meet. I am sure more than one person has learned to manage their fantasies inside once they learned what happened to the people who exteriorized their fantasies.