While I agree that everyone has that potential in <i>theory</i>, it is much more likely for radicalization to occur among certain groups, third-generation muslim immigrants in particular. And perhaps in a broader sense targeting people in particular socio-economic groups might also be useful (jobless, young, low education,etc.).<p>The way I see it, targeted surveillance of these at-risk groups should be possible, and specifically in relation to terrorism or extremism in general it might even be effective. There are volumes of studies on how radicalization occurs, or how cults work, and what problems are caused by jobless young men disconnected from society around them (both by upbringing and through various forms of racism&#x2F;classism, hidden or otherwise). The process is not exactly mysterious.<p>That said, I get the impression that there&#x27;s a huge gap between what researchers know about these processes, and how this is used by police, &#x27;neighborhood watchers&#x27;, and schools, and possibly even intelligence agencies.<p>I&#x27;ll also add that regardless of how effective targeted surveillance might be, on a &#x27;gut&#x27; level I feel uncomfortable with this scenario and would not be in favor of it. I can&#x27;t quite articulate why at this point, but personally I&#x27;d still prefer not significantly changing our way of life over the, so far, infrequent terrorist attacks. Perhaps the best answer is to simply not let it phase us and continue with life. Most other solutions feel like (partly) playing into the hands of terrorists. But I don&#x27;t think that&#x27;s a realistic option, sadly, and perhaps it&#x27;s easy for me to say these things without having felt the effects of such terrorist attacks personally.