The nsIContentPolicy::shouldLoad function is not called for livemarks/livebookmark loads. This is the case for both 1.8 and 1.9 branches. Filing this bug because there is no way to block or disable livemark fetches at runtime, and the content policy is one potential option. Could potentially be considered a dup of Bug 436250, depending on if one believes the content policy should have a say in all browser network activity or not.
is this still happening in the latest version?