title: Privacy control using Zend
body: <p>I am making a social website using Zend. The site allows users to become friends and access each other's profiles and blogs. I also want users to have control over their privacy, which can take parameters "Friends Only" and "Public". I looked at Zend_Acl but it seems to be only able to to handle single user's accessibility not users have relationship. Any ideas about the best way to do this?</p>