There are some circumstances when you want to post status on your timeline but it's too sensitive an issue to discuss or comment. I'd like to propose an anonymous timeline, where people write status as anonym, and only their friends can see the status. Thus people will feel free to comment and share opinions. Moreover it might induce some extra fun. But still, it might cause intemperate argument and even abuse since no one knows who sent the comment. That why the anonymous timeline is only shared between friends.