Thy don't need to walk into coffee shops. They just drone strike 'em.
Furthermore, I would ask you: just how desperate does someone have to feel to put on a vest to go blow him/herself up? Sure, some are brainwashed, but how far can that actually go statistically to make someone do that? If I were the mother of any of those children in the video in the original post, god knows how far I might be driven with crazy rage to attack someone who I thought was responsible for that. When you have nothing and nobody left to care about, crazy things can take seed in your mind. We are all human.