Honestly, yes.<p>If someone wants to kill lots of people, they'll find a way.  There are no metal detectors in a train station, but a bomb on a speeding subway car is just as lethal.  There are no metal detectors in the mall, yet it'd be trivially easy for terrorists to fire off a couple shots in a mall and then mow down people with submachine guns at the exits.  There <i>used to be</i> no metal detectors in schools, but then some teenagers found out it was trivially easy to kill lots of people there too.<p>The only reason I can think of why planes are any different is that a plane crash is much more sensational.  "300 killed in mall shootout" would make headlines, but it doesn't inspire the same fear as "300 killed in downed airliner", particularly since it's virtually certain you'll die if your plane blows up in midair.