At one time a whole population lived under a rock somewhere. Now they have come out and gather on the internet where they can encourage each other and goad each other on.
Someone who would never imagine acting out his or her sick thoughts can now accomplish them and feel good about it.
In our society we accept the fact tens of thousands die on our roads each year. That's just a de facto thing. Some day someone is going to write a dissertation and calculate how many die because of the internet.