If there is one thing I have learned over the years it is that one must lie to customs officials on principle. They are part-cop, part-bureaucrat, all cold blooded, rule lovers. Like cops, customs officials have a great authority, and equally small brains (lizard-like in body: brain mass I believe). But unlike cops, they have no power to make judgment calls. Their power comes from the faithful application of a dry set of rules, and the rules of the customs official variety never reward honesty. With a cop, if you bullshit him or her minimally you may get on his or her good side and they can let you off. With a customs official, you might as well lie because there will be no additional penalty beyond whatever you had coming pre-lie.
In the trip back from Tanzania, I deviated from this maxim to great woe. The problem was that I was in Amsterdam, and the cool-laid back reputation (really misconception), clogged my vision of a icy, all too Teutonic reality. The customs official asked me if I had any pornography on my computer. My first thought was that she was checking to make sure I had enough porno on my computer, or perhaps suggesting that we make a film. I admitted I did not have any pornography on my computer--and then as an after thought, I said "well, maybe there were a few pictures of my wife on a vacation, but no, in fact, no pornography. No nude photos at all actually." The customs people took that as "yes, I traffic in kiddie porn," and directed me out of the line and into the room of suspected kiddie-porn fiends. Of course, they were all regular dudes eager to get their Amsterdam vice of choice on. We sat in the kiddie-porn fiend detention center while Interpol went through our hard drives. I have 150 GB on my laptop. These guys all had laptops and digital cameras. It suffices to say that we were in the detention center for sometime before we were all exonerated.
And the best part is, literally, in my other hand from the laptop, I had all the blood samples from the Tanzanian malaria cases. And of course, the many CDC permits for said specimen transportation were partly in checked luggage, partly missing in conjunction with KLM's free Heineken, and otherwise wholly in disarray. No notice was ever taken of the blood specimens, and after the porn search I was in no mood to mention them.