> but I also think it is reasonable for law enforcement in the investigation of said crimes to also investigate links to other members in the movement.
It doesn't work. Every single time a radicalized member of the marginalized community does this kind of crime, the numbered-letter-agency dutifully reports, that they knew the person to be radicalized, but had nothing to act on, because a lot of people have weird violence-approving beliefs, talk about them openly or with friends and very few actually hijack a Boeing or two. Those who plan to do things also happen to learn about op-sec mistakes of those caught before them.
Israel knew about Hamas, and the russian empire of 19th century knew about anarchists. Pouring a lot of resources into suppressing all of that didn't do jack shit in the long term.
It doesn't work. Every single time a radicalized member of the marginalized community does this kind of crime, the numbered-letter-agency dutifully reports, that they knew the person to be radicalized, but had nothing to act on, because a lot of people have weird violence-approving beliefs, talk about them openly or with friends and very few actually hijack a Boeing or two. Those who plan to do things also happen to learn about op-sec mistakes of those caught before them.
Israel knew about Hamas, and the russian empire of 19th century knew about anarchists. Pouring a lot of resources into suppressing all of that didn't do jack shit in the long term.