> Then when a user visits a site, P3P will compare what personal information the user is willing to release, and what information the server wants to get – if the two do not match, P3P will inform the user and ask if he/she is willing to proceed to the site, and risk giving up more personal information.[4] As an example, a user may store in the browser preferences that information about their browsing habits should not be collected. If the policy of a Website states that a cookie is used for this purpose, the browser automatically rejects the cookie.

This sounds ideal, or at bare minimum, vastly superior to preferences boxes which take 10+ seconds or more of JavaScript to load, and impede access to content, (and sometimes don't load properly and never go away).