How do I block someone?
Click on My Profile at the top of your page. From the dropdown menu select Account Settings. A new page will appear with several options. Click on the Privacy tab to open your Privacy Settings. The first thing you will see is the Block List section. Just the yellow Add New Person link. When the text box appears input the Username of the person you want to block. Scroll down and click the black Save Changes button.
You can also block another user by navigating to his profile page. Just below his Profile Pic you will see several text links in yellow. Click on Block this person. The member is now added to your Blocked List.