Facebook blocking problem?

[pri✍]

When you're block by someone, neither of you can see each other. But if that someone unblock you, while you might not aware of it, they can see your profile; in order to prevent that, you may want to block them as well.

How to?
Block someone, AB, who already blocked you:
1. Ask your friend to go to AB Timeline, the person who blocked you, then copy the URL address, say it's
https://www.facebook.com/xyz;
so the email address for that account will be
xyz@facebook.com

2. Go to Account Setting ➤ Blocking ➤ Block users ➤ put that FB email in there ➤ Block.