Ummm... always?:

The student is Star Simpson, a 19-year-old MIT sophomore. On Friday, she went to meet a friend at Boston's Logan Airport, but made the mistake of wearing her Career Day outfit: a sweatshirt to which she'd attached a circuit board, light and battery... What happened is so grossly wrong on so many levels that I hardly know where to begin. Since when did a circuit board on a sweatshirt look like a bomb? Since when did suicide bombers walk around with bombs on the outside of their clothing? If the people in charge of protecting us are stupid enough to think this, how hard would it be for real bombers to fool them? More importantly, since when was it okay to blow away someone who posed such an ambiguous threat? And if she really did have an easily-detonated bomb, wouldn't shooting her -- rather than, say, paralyzing her -- pretty much guarantee its explosion?

(1) No. Shooting her in the head would not "pretty much guarantee" the bomb's explosion. More whatever the opposite of the word "guarantee" is.

(2) It wasn't just a circuit board. It was a circuit board connected to wires and batteries, strapped around a girl who was in an airport for no reason other than "picking up a friend." We're not sure what the standards are for "analogy" in the sophisticated parts of this country, but doesn't that seem like it qualifies as "enough of a bomb to justify pointing a weapon at the person dumb enough to wear it to an airport"?

(3) We've ranted about this before. It sounds very smart and sophisticated to say "no bomber would be stupid enough to be this obvious." Which is true, unless bombers know that the easiest way to walk into a place and bomb it is to make it really obvious that you're a bomber.

References:
* Boston Airport Bomb Scare Should Scare Scientists [Wi Sci]
* A Polite Request From MR: Can Everyone Please Stop LeavingThings That Look Like Bombs In Public? [MR]

Previously:
* Democratic Recommendations For Israeli and American Jews
* US Public Diplomacy, Tact Don't Extend To Israel
* These Conspiracy Theories About Cho Are Still Stupid