Unfortunately, this "secondary inspection" is a pretty standard procedure for the Department of Homeland Security. Even though the situation is much better now, a couple year after 9/11 - all non-American males (and some females) will have to go through this secondary check.
The process took 2-3 hours, we have to sit on a room where we can't use our cellphone, and wait until we are called. Then comes the interview, which should be pretty easy if you have nothing to hide. Sometimes you have to show your credit card, letter from school/company, friends/family # to verify, etc. We have to go through this every-single-time we enter the border. Tedious, but that's the norm....
Nowadays they are more lenient on this secondary process, but if you get lucky - you'll get a taste of this "welcoming party" :)