But they create an environment where terrorists can exist.
They are part of the problem. Just like people who see a wanted bomber and don't call the police.
And I don't mean to be rude either by pointing it out to you, even though you may have family like this.
Family is family. If he did what he is accused of, then he should be prosecuted. However don't start asking me to turn family and friends into the national government. But I don't think you're going to be able to understand the mindset of folks like this. They did it to protect him.