I think this is right. There's a (let's say) 0.01% chance of false positives and being detained and hassled by FedGov border cops, and this guy was in that cate

I think this is right. There's a (let's say) 0.01% chance of false positives and being detained and hassled by FedGov border cops, and this guy was in that category. It's not just American border cops. Like the parent poster, I had bad experience entering Canada. I truthfully told the border agents I was a journalist arriving to speak at an Internet law conference at the University of Ottawa's law school, but I didn't ask the conference organizers for a written invitation and therefore couldn't produce one. The Canadian border guards took me to a side room and interrogated me what seemed like an hour. It was an unpleasant experience, especially given the uncertainty about whether I'd return home or be able to enter the country or be banned from entry for a period of time. My now-spouse was living in Canada at the time, so the last option would be the worst. They did make a pretense of looking on the school's web site for the conference, but (from what I could glimpse) were looking at the French version, not the English version where the conference was actually listed. Or maybe they found it and were intentionally playing dumb. Eventually I was admitted. Ironically, the conference was sponsored by the Canadian government!