The lack of rights one has when traveling through an airport is genuinely scary. As far as I'm aware once you start the security process I don't believe you can actually stop it without some similar interrogation like this.

I remember a while back I believe it was New Zealand that wanted the ability to search your devices for BitCoins. I believe at least in the UK it's a criminal offense to not provide the password to your encrypted device. Unless things change I'm sure this will just get worse.