There are several reasons why someone may vanish from your list of Facebook friends. Being blocked by that person is certainly one of those reasons, but it isn’t the only one. The person may have unfriended you or deleted his Facebook account. Facebook won’t notify you if you have been blocked, but using Facebook Search, old messages, mutual friends and the Facebook public directory, you can often gather enough clues to determine whether or not you have been blocked. Writer Bio

How to Find Out If a Facebook Friend Blocked You - 84