Cyber Bully on facebook please help me get rid of him?

[Cassius]

Go onto your privacy settings by clicking the little cog on the top right hand side, then change a whole bunch of it so your account is more secure.
You can do things like:
Changing who can see your posts,
Changing who can look you up,
etc,
I'd even go onto Security which you will see under Privacy settings on the privacy page and change some of those.
That doesn't have to be permenant, after a few months the person may have left you alone.

However if this doesn't work, remove your account and start again; new URL, new profile picture, refreshed information and select your friends wisely. ;D Good luck!

Also remember Cyber bullying is illigal I appear to remember, as ridiculous as many people see the concept as, report this person, if you know who they are... and let the fun ensue!