As for content on your Kindle, obviously Amazon is aware of books you purchased on Amazon. Other books on your device could have been purchased elsewhere.
If you have ebooks on your Kindle that were obtained illegally and if Amazon had some way of determining this, I doubt very much that they would ever become a police for publishers and report their findings as this would kill Kindle sales.
But yeah, if you're concerned just don't turn on wireless after registration.
Last edited by JoHunt; 11-14-2012 at 02:57 AM.