During the pre boarding process on UA 947 from AMS we experienced what seemed to be an unusual amount/type of questioning. This has never happened on trips to other European cities so I was wondering if this is something peculiar to AMS? After security, but before going to the secondary waiting area (and through a second Xray screening process), several security officers were stationed to examine our passports and boarding passes. We were asked many questions beyond the usual ones regarding who packed our baggage and whether anyone had asked us to carry something for them. We were required to produce our hotel receipt to PROVE how long we had been there and where we had stayed, and the security officer studied it carefully. He asked if I was a frequent flyer with "this airline" (information that's on the baording pass), and which level I was. To me, these are unusual questions for security - and they weren't sociable - he was quite stern throughout the interrogation. Is this usual for a departure out of AMS?