I keep hearing that the constitution doesn't apply at the border, but it seems too incredible to believe. To the question, "Do you know anyone that is a terror

I keep hearing that the constitution doesn't apply at the border, but it seems too incredible to believe. To the question, "Do you know anyone that is a terrorist?" I would have to answer, "Probably" or at least, "I don't know." I could not truthfully answer, "No." Neither could just about anybody. It seems pretty clear to me that it would be improper to detain somebody because their phone was too clean and they do not know if they know anybody who is a terrorist. Can anybody point to actual case law that supports the claim that such persons are not protected by the constitution? There is a lot of scaremongering in this area, but I haven't seen any actual case law. Of course, I haven't paid much attention either. But the only cases I have seen have been decided in favor of the citizen. I'm pretty sure there is a limit to how long a Highway Patrol officer can keep me on the side of the road without an arrest or a ticket. I know there is a limit to how long I can be detained by police without being charged. There must be a time limit to how long CBP can take to ask me 800 questions. Or rather, how long they could detain me while I answer 0 questions and repeatedly ask for an attorney. I am glad there are people willing to spend the time to hold them accountable when it would be easier to just move on and try to forget the whole thing.