You do have to be careful I found out (the hard way). While traveling this weekend I had an airport security lady pat me down really hard. It pissed me off, so I said "Damn lady, it's not like I have 10lbs of C4 in my shoe". She looked at me and for some stupid reason I thought for a second she might not know what C4 was. So I started hopping up and down on one foot saying, "You know, it's not like I packed my shoe with explosives, back off".
I found myself in a room with 4 unfriendly gentlemen who roughed me up... asking me things like where I was from, what nationality was I, did I ever renounce my citizenship. I tried to lighten the mood a little because it was getting pretty tense. I told them the only time I could remember renouncing my citizenship was when Clinton took office and wanted to take my machineguns away. I realized the folly of that comment as it rolled off the tip of my tongue. I had my fingers damn near folded completely backwards and they hit me in the side with some device that totally screwed me up.
They asked me again where I was from. At first I thought they were kidding, so I tried a cheesy middle eastern accent and said, "Saudi Arabia dude". I mean seriously, I'm white as all hell and 6'3. I thought they would see the humor in that. Well, they didn't because it seemed to antagonize them a little, so I backed off. I tried to convince them that I was really from Kansas but they wouldn't believe me at this point.
Things calmed down a bit after my strip search. While I was getting dressed the guard watching me seemed nice enough. We were chatting about recent events and I said, "Wouldn't you shit if after all of this I had swallowed a couple of ounces of C4 and blew the shit out of my flight?".
That didn't go over real well... call me a bad judge of character I guess. This guy came UNGLUED and back to square one I went. They screwed with me for 6 hours straight. I even got on the local 10 o'clock news.
I'm not flying anymore after that. I'm thinking about suing airport actually. I was totally abused... and those idiots had no sense of humor.