My heart goes out to Britain, but they have shown us all the guts to withstand such attacks over the decades.  It is difficult to deal with attackers who are home grown, like in this case.  Such was the case with other homegrown attackers like Bissonette, most recently in this country, and Breivik and McVeigh.  It is impossible to know when such a social time bomb will go off.  We must all be vigilant.