It is only a crime if it rises to the level of physical threats or some other high level of harassment where the person is feeling physically threatened. If you know who is doing the bullying, you can ask a lawyer to write a cease and desist letter.
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You have given us nothing to analyze. CyberBullying has come to mean "anything on the internet that makes me unhappy." Without paramaters, all we can tell you is to ask the host to take it down. Actually, FB is almost too responsive about that and they probably will if you ask.
Best to you and I'm sorry this is happening.
Cyber Bulling is a relatively new thing and the law is slow the adapt to changes in our world and technology. Whether it is a crime or not is determined by the same laws and tests as for normal bullying. There has to be a reasonable, objective belief that you are in imminent danger for your safety, life, or risk of bodily harm. This is a basic test. Most likely there is not a crime (absent more information on your case) here. I would contact Facebook and have them look into it.
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