Unlike famous mass shootings and stabbings in recent years by depressed or mentally disturbed individuals, most jihadi fighters don't have such problems. The fact is that jihadi terrorists usually turn out to be otherwise normal people. They are as rational as you or me, and people can't seem to accept or understand this. Just look at the numbers of Europeans travelling to Iraq, Libya, Syria to fight, to sacrifice their lives for this ideology. Or the tens of thousands who are already in ISIS. You can't tell me that most of them have mental problems.

A major problem in Europe is that there is no challenge to jihadi rhetoric, except for the far-right freak show, because the whole thing is taboo. You can't defeat jihadi ideology by pretending it doesn't exist, which is what you're effectively doing when you restrict online access and communication. It's a knee-jerk yet cowardly way to avoid confronting the problem.

Everyone is influenced by rhetoric (to some degree). Everyone has irrational weaknesses. It is one of the reasons why a monopoly on communication is very dangerous.

So would you also ban books about it? News articles maybe?