One of the reasons I have sometimes preferred an IM such as Yahoo over Windows Messenger or MSN Messenger is I can delete contacts and even delete the entire account. It takes thirty days or so before they actually delete it, but it's then gone. With Messenger, I never am able to delete the account as it seems to be tied to my Windows Live ID or my original hotmail email.
But, my main question is when you go to options and privacy and you see a list of contacts which you have blocked and deleted from the main window you can only delete some of them. Even over a year later, you the delete option is greyed out on some but sometimes one that you couldn't delete is deletable. Is there anyway to permanently delete a contact that you added? And, what makes a contact deletable? I hope this is clear enough.