A backpack bomber was foiled at the annual footrace in Spokane by a young woman who saw an unattended backpack on a park bench before the race and called police. It was indeed a bomb. How many other people saw it there and thought nothing about it?
Leaving a backpack on a bench where hundreds of people are lining up, giving their jackets, etc to family or friends, or maybe just leaving them on the ground...almost too easy.
Can you imagine the mass chaos that would be caused by coordinated suicide backpack bomb attacks in subways during rush hour in a half dozen cities? I’ll stop here because I don’t want to give the bad guys any ideas...
Israel has taken even a brown lunch bag very seriously for decades.