Block a User on Facebook
Step 1: Log on through the Facebook home page and head to the page (see Resources below). You can change privacy levels for almost every Facebook feature from this page.
Step 2: List the person you want to block in the "Block People" box on the My Privacy page and click "Search."
Step 3: Browse through the results to find the person you want to block. The more common the name, the more people you will need to search through.
Step 4: Click the "Block Person" link for the person you want to block. The person will no longer be able to see your profile, and you will not turn up in the person's search results.
Set Up a Limited Profile
Step 1: Go to the "My Privacy" page after you log on to Facebook.
Step 2: Click on the "Limited Profile Settings" link. You will see a preview of your profile along with a list of all the shared features.
Step 3: Choose the profiles features you want to share on your limited profile. You may also decide which photos albums you want to share. Don't forget to click "Save" when you are finished making changes.
Step 4: Add friends to your limited profile network by listing their names in the limited profile box. You can only add confirmed friends to the list.
Block someone who has setup own privacy settings to their limits
Step 1: You cannot block him/her