The answer is in your question ;)
We love birthdays, when's yours?
Will not be displayed on your profile. (Why do you need my birthday?)
Formspring requires all users to provide their real date of birth, but it is used for internal purposes only. This information will not be displayed on your profile, and its use is governed by the Formspring Privacy Policy
You don't follow . Sure you want to view this image?
We will never reveal your name to the person you ask.
Even if you hide your name, keeping Formspring fun is still your responsibility.
