I just came back from traveling in Europe. Going to Luxembourg via Frankfurt, I went through a metal detector once (in Kansas City, not in Detroit or Frankfurt), I filled out exactly zero paperwork, and answered exactly zero questions from border guards and customs inspectors.
Returning (via a layover in Amsterdam), I had to go through three metal detectors (Luxembourg, Amsterdam, Detroit). In Amsterdam, I had to answer bizarre, irrelevant, personal questions, as did anyone else who wanted to fly west across the Atlantic, then have all my passport data carefully copied into the airline's computers, then fill out a customs form, then answer the same irrelevant personal questions in Detroit, then answer questions about my purchases in Europe.
Now, before you tell me that America is at war with terror and the EU isn't, let me note some interesting facts. First, al Qaeda attacked the EU twice, on 3/11 and 7/7. Second, Europe has a long history of dealing with domestic and international terrorism, and dealing with smuggling of contraband goods. They understand the threats and are dealing with them. If they needed to ask personal questions to keep themselves safe, they would. The Europeans have even arrested and convicted several al Qaeda cells, something the US is having a harder time accomplishing.
Third, I noticed a nuclear power plant while we were flying over the Rotterdam ports. Those ports are the busiest in Europe, so I imagine a 9/11-style terrorist attack on that plant would be pretty disastrous for the world economy.
And yet the nice people of Luxembourg didn't need to know the name of the person I was staying with in their Grand Duchy. Nor did they need to know every detail of when and how I packed my luggage, and how large the box of chocolates is that I packed. They X-rayed my luggage, made sure I wasn't carrying any metal, and determined I wasn't a threat.
Who I stayed with (a question I was asked twice, in Amsterdam and Detroit) is not anything I'm ashamed of. There's nothing illegal, illicit, or even questionable about it. It just isn't anyone else's business.
And asking it enhanced security in exactly no way. I answered honestly, though for the life of me I don't know why. If I said I spent the last night with Osama bin Laden or with Nicole Kidman, would they have had any way to check that? And if I actually had spent the night with either, would I tell some underpaid rent-a-cop at an airport?
The question has no security value at all. Perhaps it was meant to throw off terrorists with carefully memorized stories, but they can make unverifiable facts up as well as anyone can, I expect.
So, I had nothing to hide, but I still objected to the questions, as should you.