Someone is harassing me on Facebook. What do I do?

"The most efficient way to report abuse is to do it in the same place it occurs on Facebook. For example, if you receive a harassing message in your Inbox, you can report the message by clicking on the "Report" link next to the sender's name as you are reading the message. If you receive a harassing message from a person who is a Facebook friend of yours, you should remove the person as a friend and report the message. Reporting the message as harassing will automatically add this person to your Block list. You can also use the "Report/Block person" link that appears at the bottom of the abusive user's profile. If you learn that someone is continuing to make abusive comments about you even after you've blocked them, you can ask a friend to report that person on your behalf. Reports are confidential and the user being reported does not know that they have been reported. After a report is submitted, we will investigate the issue and make a determination as to whether or not the content should remain on the site based on our Terms of Use. A Facebook administrator looks into each report thoroughly in order to decide the appropriate course of action." - The Facebook Privacy Page

Someone is harassing me on Facebook. What do I do?