After my airport security complaint the other day I found this interview of the head of the TSA by Bruce Schnier really, really interesting.

I just found a pocketknife in my laptop bag. This is not unusual, except I remembered that I must have taken it with me both to and from Houston earlier in the week, passing through security both times with a 2 inch blade in my bag. This happened once before, but was caught on the return flight. Total I have passed through airport security at least 4 times with a forgotten pocketknife, and only once did they stop me. A 25% hit rate? That’s just going to frustrate me more next time I’m standing in a security line for an hour.