Every country has borders that are controlled in someway or other. Travelers usually bump into the border patrol when intentionally crossing the border using a plane or train. Sometimes this is as simple as just checking for a valid passport but other countries are a bit testier and require additional visa’s for some people but require even more additional forms and special invitations from others.
When crossing the border you want to own a “good passport” which simply requires an annoying wait rather than other “less good passports” which usually has some pretty unsavory alternatives to a long wait. It is bad enough to be pulled aside, as there is always the possibility you will miss your connection but if you look suspicious enough you will get questioned.
Why are you coming here?
What are you bringing with you?
Were you ever involved with political groups that we don’t approve of?
The more suspicious you look the longer the process will take, and the more rigorous it will be. A friend of a friend was suspected of smuggling something into the US and so he had quite a long chat. That eastern European passport meant he could have been importing Dracula, non-pasteurized dairy products or any other products so the border control decided to strap on a pair of rubber gloves and check very thoroughly.
As an honest passenger, this is probably the worse it can get, you miss your flight, you are detained with plenty of non-relevant questions and then you are physically violated.
Well, this poor soul had it worse than probably any other due to sloppiness. It was the end of a shift and it turns out that the people doing the body cavity search forgot to properly fill out the paperwork or handover this case to the next officer at the end of the shift.
So the first thing the new officer did was to question the individual and then see that it appears he has been selected for a body cavity search. This of course make the patient very agitated and thus somewhat suspicious which of course made it look like he had something to hide and thus ensured that he was searched a second time – probably quite vigorously.