They shouldn't have been arrested. They should have been handcuffed in a field, to their handler, and detonated.
Oh, I think Shin Bet wants to have a little chat with these fine folks. You know, get to know them, their hobbies and interests, and their choice of friends, if you get my drift.
No, I'm sure they're pouring lots of coffee for these guests of theirs, because there is so much to talk about!