Mem Fox, an Australian author of children's books had a harrowing experience:

http://www.newyorker.com/books/page-turner/an-australian-childrens-book-authors-harrowing-interrogation-at-lax

Kjell Magne Bondevik, a former Prime Minister of Norway (a NATO member), was en route to the National Prayer Breakfast when he was detained and questioned:

https://www.washingtonpost.com/news/morning-mix/wp/2017/02/03/former-norwegian-prime-minister-detained-at-dulles-airport-for-an-hour-he-visited-iran-in-2014/?utm_term=.648d45cd7778

Juhel Miah, a British teacher, was bounced off a plane for no reason (other than being Muslim):

https://www.theguardian.com/us-news/2017/feb/21/british-muslim-teacher-taken-off-us-bound-flight-i-was-treated-like-a-criminal

Now, Canadians.

Visit America? Just say no. Too risky.