Your question leads us to believe that you think you know your harasser. If so, you need to think about whether this person is acting in or out of character. Are you arguing or involved in hostile confrontations offline? If you are, you will proceed differently than if this conduct is out of the blue.

1. Determine whether this is the person you know or a poser. If it's a friend and you have no idea why they suddenly starting attacking you online, it may not be your friend doing this at all. When "friends" are involved in harassment and there is no offline argument, it might be someone trying to get your friend into trouble by posing as them. If it's not them, but a poser, reporting them to Facebook or the school or the authorities will end up helping the harasser accomplish their goal - getting the target (your friend) into trouble. Just to be sure, we recommend taking it "offline." That means calling them up or talking with them face to face. If they are upset with you, you'll know. If they have no idea what you're talking about you know the real harasser is still "at large." (If you IM or text them, or message them on Facebook and their account is compromised, you'll be getting a response from the poser, not your friend.) If you are certain it's not a poser, and they are harassing you online by posting malicious or hateful things on Facebook, proceed to step 2.

2. Don't let them see you sweat. They are looking for a reaction. They want attention - yours and everyone elses' you know. Don't give it to them. Often they will go away when you aren't responding the way they want you to. Instead, take control. Report them to Facebook. It automatically deletes them as a friend and blocks them from viewing your profile. Then delete the post. If they set up a new profile and try to get around the block, when you report them again let Facebook know about their tactics using the report/block function. Read on to find out how to report, block, and delete.

3. Talk to a parent or trusted adult. We strongly encourage you to talk to a parent or a responsible adult (your older sibling, aunt, uncle, guidance counselor or your friend's parents are often good choices) immediately if someone online says or does something to make you feel hurt, frightened, uncomfortable or threatened. This is especially important if you are under 18. You shouldn't face it alone. Besides the only people you know for sure are not involved in the harassment are your parents or trusted adults.

4. Report and block the person on Facebook. You can notify Facebook of the harassing posts and comments by clicking on the "Report/Block" link located on all Facebook pages. 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. A block prevents this person from viewing your profile. When you block people, any ties you currently have with them will be broken, and these people won't be able to contact you through Facebook.

   If you learn that someone is continuing to make abusive comments about you on other profiles you can't view, 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 or who reported them.

   What will Facebook do if someone is reported? Facebook will use its best efforts to review reports made through its site reporting tool within 24 hours and remove any content that is deemed to have violated the Statement of Rights and Responsibilities. If warranted Facebook will also warn or disable the user responsible for posting the abusive content. Where complaints about nudity, pornography, harassment or unwelcome contact are made by independent email to abuse@facebook.com, Facebook will acknowledge receipt of the complaint and begin to address it within 24 hours. Facebook will respond to the reporter within 72 hours of receiving the email complaint to inform them of the steps Facebook has taken to address it.

5. Delete the offensive posts on your wall or messages in your inbox on Facebook. To delete an offensive Wall post, hover over the post you want to remove, click the "Remove" button that appears, and select "Delete" in the dialogue box. To delete a message from Inbox, simply click the "Delete" button at the top of the message. Only confirmed friends can post to your Wall or send you a message through Chat. If you are receiving posts and Chat messages you don't like, you should remove the sender from your friends list and let your friends know about the problem so they can keep an eye out as well.

6. Adjust your privacy settings. Adjust your privacy settings to match your level of comfort, and review them often. The new Facebook settings allow you to choose who sees what, on a pic by pic and feature by feature basis. If you only want real friends to see what you post and keep the creeps from writing on your Facebook wall, choose a restrictive friends only setting and make sure the only ones on your "friends" list are people you trust. (If you break up with someone or get into a fight with your BFF, change your settings right away to keep them from ranting on your profile.

This information is provided by Parry Aftab, Executive Director of WiredSafety.org & Stopcyberbullying.org

For more information visit:

Facebook's Safety and Security pages.

If you think you are at risk of physical harm, contact your local police or school.

And if you need more help dealing with ongoing harassment, visit WiredSafety.org's cyberharassment helpline.