Me too. My father does and I could have easily learned as I lived in a two family home with my Italian grandparents until the age of three or four. Mom didn't think it was a good idea at the time. We both regretted it later in our lives.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .