Also, US three-letter agencies already have access to Google, Twitter, Facebook and have all necessary information, as Snowden has said, so I guess it makes no sense to provide it again.
Maybe they just are trying to build a cause to be able to deport anyone from the country or reject entry. In this case it would be better to pass a law that allows to do it.
Also this is a good reminder that you better not post too much details about yourself in social networks, otherwise it can be used against you. And Hackernews is not considered a social network, right?