I'm pretty sure it has to do with local laws covering disclosure of viewing records. The reason this is now possible in the US is that Netflix just managed to g

I'm pretty sure it has to do with local laws covering disclosure of viewing records. The reason this is now possible in the US is that Netflix just managed to get Congress pass an amendment to the VPPA (http://en.wikipedia.org/wiki/Video_Privacy_Protection_Act http://en.wikipedia.org/wiki/Video_Privacy_Protection_Act). This feature disappeared three years ago because someone sued them over an alleged violation of this law.