[Pils]

That research was published by a libertarian think tank in 2013. Since then, there have been numerous examples of lone wolf terrorist attacks where the perpetrators appeared to have no offline contacts with extremist groups. See: New Zealand shooting, Pittsburgh shooting, etc.

[fallingknife]

There were also lone wolf mass shootings before the internet, so what does this prove?

[blitzar]

That radicalisation does not exclusively happen face to face and that it can be conducted on line, by newsletter, by book, by carrier pigeon.