Facebook Reveal Auto UnBlocking Bug

Facebook publish about a blog that was active between May 29 and June 5. Up to 800,000 users were affected by this bug. This bug was active in Facebook and Messenger that unblocked some people they had blocked. According to facebook this bug have been fixed. Those unblocked users were not able to view the contents of that user, but were able to view the contents of their friend of friends.
Facebook Auto Unbloking Bug Fixed


Were you Affected

If you were affected facebook will send you notification informing about this bug. If you had blocked someone they won't be able to connect with you via messenger, cannot be your facebook friend and your contents are not visible to them. In the case of that Bug:

    It did not reinstate any friend connections that had been severed;
    83% of people affected by the bug had only one person they had blocked temporarily unblocked; and
    Someone who was unblocked might have been able to contact people on Messenger who had blocked them.
Those unblocked users were Blocked again and issue have been fixed. You can learn more about this bug here in facebook /blocking-bug/.
Facebook informing about the Bug to affected users

How to Block users in facebook

You can Unfollow users in facebook to get no contents from those users you can use the facebook News Feed Preferences Options. If You still want to block you can go the his/her profile >> option and Block users. You can go to Settings > Security and login > Block user > Search the name and block. You can also directly block from their posts. Post option > block users.

How to Unblock someone in facebook

If you had blocked someone and wounder how to unblock. here you can. Simply go to settings > Security and login > Block User. There are list of all the users you had blocked and you can unblock them just clicking unblock. Then conform. Check How to Unblock Someone in Facebook.
Thank you!