One time many years ago, I happened to have a cordless Makita drill in my carryon (due to the fact that one of my tool trunks was overweight). You would have thought I had 200 lbs. of plastic explosives. Security came unglued. A supervisor finally arrived and told me it was because I could "take the plane apart" or "breach the hull" with that. They did let me take it on board...finally.