You're probably looking for advice on graver issues, but I've been lucky with border crossings and can only offer this: when flying to the US, you technically c

You're probably looking for advice on graver issues, but I've been lucky with border crossings and can only offer this: when flying to the US, you technically cross the border at the origin airport. I lost a banana and an orange that I thought I could eat on the plane. On a more serious note, I never try to pick a fight with officials to prove any point. They can stress you out, make you miss your flight, or straight out refuse entry. Most of them know this and will abuse their power just for sport, and your defiance will only trigger this sense and give them more pleasure in hassling you.