Ask HN: How about an anonymous social network?

Over the last weeks(since all the crazy stuff regarding the NSA) I was thinking of this startup that would be an anonymous social network. Well not 100% anonymous, your profile would be public/private with your data but everything you do and all your comments to other people will be anonymous(messages encrypted even in the database based on tokens). This would also validate the idea behind you will get real answers to your questions, real and honest feedback to your photos and so on. What do you guys think of this idea, is it a valid startup?