In a sane country this would be a sufficient basis to detain these men until warrants could be obtained to conduct searches of property and computer devices. After every mass shooting there’s a wringing if hands and cries of “if only we had some indication what they were up to”. The terrorists probably have to pinch themselves when they realize how stupid western security forces really are.
I mostly agree. I remember that previously sane country.
The Western security services aren’t stupid; they are complicit. That is why there is 0.00 probability of those services doing what the law requires, what you and I expect, and what they are paid to do. That is also why there is a 1.00 probability of another terrorist attack.
They aren’t stopping terrorism because that’s exactly the way they want it.