I'm so sick and tired of the government constantly sticking their noses in where it doesn't belong. It used to be that they wouldn't get involved unless something particularly egregious happened. Now you've got a couple of idiot members of the Congress sending letters to a PRIVATELY held company, regarding a service that they provide which they do not charge for and which is completely voluntary and optional with regard to who participates and how much information they provide.
If I were Zuckerberg, I would be hard pressed not to respond to their "request" with a two-word response: PISS OFF!