I've had some astonishing questions asked in interviews lately. Very esoteric and obscure parts of C++ that if you followed good design you wouldn't even see or need to know about - and if you did, it's a short google query away. Testing esoteric knowledge rather than actual intelligence and programming ability is a complete fallacy imo. But then it goes even further at some places where you have to do a psychometric test to get in...!

At least Google's interview questions (from what I saw) made sense in their challenge. It's not stuff you would know from being an everyday programmer but it's stuff a truly great programmer should know.