Facebook is tweaking the privacy settings on its popular online social network site to let users exert greater control over which of their friends are allowed to see personal details they post.

The California-based company said it was adding features last night that will give its 67 million active users the option of selecting individual users who can or can't access certain parts of their pages.

For example, someone who uploads a racy batch of photos or lists their mobile phone number or personal email address on his Facebook page can now bar some people on their list of friends from seeing any of that information.

Previously, the only ways to block people from seeing specific content was to deny their friend requests outright or to create a limited profile.