I'm trying to empathise with them... I get why people become radicals of other kinds... but saying no music, no sex, live by the book, behead those who disagree... what part of that makes people think "I want to get into this, this sounds fun"?
The Arab world has valid grievances, which motivated 9-11 for example, but there's more to it than that.
IDK if there's really a lot, but many "bad things" are possible now because the internet let's you search for free candy vans in your area or whatever type of predator you're looking for to twilight yourself with.