You looked suspicious!... or maybe...
You weren't polite and respectful?... did you say Sir and Ma'am?... a little of this goes a long way!
Did you claim any alcohol or tobacco?... I always tell the truth about these 2 items and always take my allowed limit.
Were you dressed in a civilized manner (shirts with collars, nice and clean)
When board member Aplumma and I crossed over the the Peace bridge in June, they didn't even check our I.D!
We did get to play 20 questions with the officer coming back into the states though, plus a thorough ID check.