Christianity has transformed violent maniacs into constructive citizens. The polar opposite of Christianity is Islam. Its effect is documented in surveillance video of the formerly normal Somali immigrant Dahir Adan going berserk at the Crossroads Center mall in St. Cloud, Minnesota:
Note that like many Islamic maniacs, Adan developed his radicalism stateside. If we are going to import unassimilable numbers of immigrants from Islamic countries, screening is better than not screening, but not by a whole lot.
On a tip from Dragon’s Lair. Hat tip: Vlad Tepes.