> Actually I have not heard that happening even once!

Have you heard that happening more than once?

Having your luggage searched, long interrogations, dog sniffing, and then more interrogations - that has been common on international borders. All for no other reason than the border guard didn't like your face. That's my real life experience as a person who used to travel a lot. And many others I've met told similar stories, including being denied entry. So it's been a coin flip for a long time.