Here's the logical problem with the profiling. Suppose the following were true.

All the 9/11 terrorists were men.

All the 9/11 terrorists were between the ages of 20 and 25.

All the 9/11 terrorists used LLBean Luggage.

All but 2 of the 9/11 terrorist were practicing Muslims.

Proposition 1. Therefore, to maximize our chances of catching future terrorist, everyone who meets _one_ of these criteria should be checked.

Proposition 2. Therefore, to maximize our chances of catching future terrorists, everyone who meets _all_ of these criteria should be checked.

Argh -- hit the wrong button again. I meant to kill the whole post, because it's going on too long.

To wrap it up if you work out the probabilities, Proposition 3 is correct.

The argument in favor of Proposition 2, is based on the assumption that LLBean owners, as a group, are more similar to one another (in murderous intent) than non-LLBean owners. This is not true, nor is about the age group, nor the religion (it may be true about men).

If you work out the math (which I'll skip), you are better off searching k percent of the general population, not k percent of the subgroup.

Triple arg: Proposition 3 is, search the general population at random.

I give up. I'll quit posting and get some coffee.

Try going through security in a wheel chair.

What gets me is they still push me through the metal detecter. I'm in a metal chair of course it will go off!

I always go through security in a wheelchair (I have a disability and cannot go through the arch) and I'm always physically searched. Yes, very efficient..but I would never do it in private, too much for me !!!