I not surprised as it happened to me in my country quite few times. " Why you going that often?", "do you know somebody there?" etc. Most drastic was when I was subject of such interrogation while coming from completely different destination, just because Thai stamps in passport. Twice I had my luggage searched and was questioned why my travel diary has small child photo on the cover!!!!!
I did not have phone searched but was asked once to show pictures in my camera from recent trip. And my country is considered paragon of being liberal mind you!