No, it's not the neighbors not having a backbone, it's their lack of confidence in local law enforcement, AND, that they probably know that their reports would be dismissed as mere concern or fears or even nuttiness by the local police.
What can any neighbor actually report? That people are coming and going? This article describes one clear cut case of the need for federal intervention nationwide on groups who are formulated upon the principle of "violence" and opposition to the U.S. as "culture." I think that's the key thing here, that there's clear intent by the organizaitonal principles alone of this/these groups to destruct the nation. It seems that's the ongoing principle I read by most muslims, unfortunately, to destroy that and whoever that is deemed to be oppositional or even non supportive of islam.
Didn't England recently ban the "preaching" of terrorism?
Think the US should do the same immediately. Then you can begin arresting these groups.
maybe so, some 'personal detective work' always works.