The actions of the police bear explaining, however, regardless of how suspicious they though the actions of the traveler were. IANAL, but as I understand it, if

The actions of the police bear explaining, however, regardless of how suspicious they though the actions of the traveler were. IANAL, but as I understand it, if police handcuff him, he was being arrested, which means the police failed to read him his Miranda Rights and to charge him with any crime. If this is so, isn't that either a crime on the part of the police themselves or at the very least a serious administrative violation? The alternative is that he was being detained for questioning, but is it really usual or accepted to detain someone for a long a period of time and handcuff them for questioning? (seems 20 minutes is considered already fairly long for this sort of detention: http://criminal-law.freeadvice.com/criminal-law/arrests_and_searches/arrest-detention.htm http://criminal-law.freeadvice.com/criminal-law/arrests_and_... , though I can't verify the source ). The question here is under which law or authority can someone be hand-cuffed and deprived of their freedom - however briefly - just for having a bunch of cards with words and a book. I mean, I am not kidding myself, the "threat of terrorism" has been used to justify far worse abuses, up to and including torture and extra-judicial prisons. But expected or not, this should be morally and legally indefensible. Also, at a personal level, it makes me think that, should I decide to travel any time soon, my reference papers for work in computer systems' security, the book I am reading on the NSA/Snowden material and my textbook on introductory Chinese should all stay back home. Because "that sure looks like some suspicious literature right there, doesn't it?"