Nietzsche said that insanity is the rule in groups and the internet was invented to create more groups.

A juxtaposition of thoughts.  In Beyond Good and Evil Friedrich Nietzsche said:

In individuals, insanity is rare; but in groups, parties, nations, and epochs it is the rule.

On 14 September 2008, Tim Berners-Lee (inventor of the world wide web) said

The Web does not just connect machines, it connects people.

The more groups, according to Nietzsche, the more insanity.  It is not obvious that he was wrong.  

One might therefore conclude that the crowning achievement of the modern era, the connecting of all humanity together via the internet, was the mere prelude to a rise in insanity owing to there now being so many more connected groups.