The first thing you need to know about airport security is one simple fact. No matter where you are and what you're doing in terminals, you can assume at least one camera and several pairs of eyes are watching you.

It can be reassuring, but at times, a bit disturbing. For instance, on a recent arrival to check in for a flight, we stopped just inside the terminal doors to get our bearings and be sure we had the right documents for getting through screening.

As we were doing it, we noticed a stack of three or four suitcases just a few feet away. We didn’t think anything of it, but suddenly two big airport cops and a huge German Shepherd dog came rushing toward us. They rushed past to swoop up the unattended bags and were gone up the nearby escalator before we could say or do anything.

No more than 30 seconds later, a distressed woman was circling the empty area where her bags had been. She said she had only left them for a short time to get some information from an airline counter, about 20 feet away. We told her about the cops' quick grab, and the last we saw of her was when she went dashing, crying and cursing up the escalator.

Later, as we made our way to the security area, we told cops there what had happened. They proudly assured us that every square foot of the entire Las Vegas terminal was covered by live cameras and trained spotters. They said the woman had committed the offense of leaving her bags unattended, even if it was for a minute or less. It would cost her a fine of $500 to get her bags returned. If she was cursing before, we could only guess what she said as she paid the fine.

That's just one example of what you can expect whenever you enter an airport terminal these days. Avoid such troubles by just following the posted rules and the eyes will be there to protect you. Disobey the rules, and the eyes will be there to nail you.

Of course, the most critical moment each traveler must face in airport security is going through the prison-like frisking and searching ordeal of the x-ray machine area. It’s vitally important that you understand in advance what is expected of you when you're in that line, including what you may or may not take on your flight. The list changes frequently, so it’s is your responsibility to keep up on the information. Usually there’s a big trash can nearby, and we’ve been forced to toss away many bottles of water.

On another recent flight, after my wife's carry-on suitcase had gone through the x-ray process, she was pulled aside by two stern-looking guards. They did the magic electronic stick search of her entire body, and then began working on her opened suitcase. Clothing and other items went flying all around, as they seemed to be looking for something very dangerous. Other cops came over and joined in the clothing-in-the-air toss.

I had visions of visiting my wife in Alcatraz or other federal prison for carrying something evil in her suitcase. Finally, I got one of the cops to talk to me. He said there was mercury, a banned substance, somewhere in her suitcase. Mercury is often used in explosives, hence my wife was a suspect in transporting dangerous materials.

Moments later, one of the cops triumphantly held up the offending article ... a medical thermometer with a tiny mercury tube. With nervous laughs all around, and without the thermometer, we were permitted to go to our gate and board our flight.

Whenever you fly today, you can expect delays and searches because of security. We all know it’s so tight because a small group of suicidal religious freaks are holding millions of world travelers hostage. Unfortunately, those nutcases believe murdering innocent people is their way to qualify for their 72 virgins in whatever they consider heaven.

Although we often can’t help being impatient with airport security people, we should be thankful to those guardians who keep our flying safe. We should also appreciate our GIs, who are sending many of the potential terrorists to join their virgins before they can try to blow up more airliners.