Yes, a lot of people don't understand that.

To make it concrete: Do you skip screening of the young pregnant Irish woman? I hope not. That was Anne-Marie Murphy, whose boyfriend put Semtex and a timer in her bag. [1]

Do you skip screening of the attractive blonde woman? Sorry, that was hijacker Leila Khaled with a blonde wig and hidden grenades. [2]

(These are both very interesting stories and I recommend reading the links below.)

[1] http://en.wikipedia.org/wiki/Hindawi_affair

[2] http://articles.baltimoresun.com/2001-09-28/news/0109280226_...