FB & Twitter Integration - Privacy Issues?

I am trying to decide whether to upgrade to iOS 6 on our devices and have a question about Facebook Integration.

I don't have a Twitter account and am wondering about the integration and API with iOS6. Specifically, If you don't have a Twitter or FB account and don't sign-in/integrate, are we SURE that Facebook & Twitter don't get any of our information/data/etc? I assume they don't but I am not a developer and don't know anything about API's etc.

I'd love to hear from someone who knows about this kind of stuff.