I have spoken to some victims who have consulted with attorneys who want a significant sum of money to get involved, even at a basic level.
Also, please be careful not to retaliate – or do anything that might be perceived by an outsider to have contributed to the problem.
Do not respond to the cyberbully except to calmly tell them to stop.
If they refuse, you may have to take additional actions.
Many web sites expressly prohibit harassment and if you report it through their established mechanisms, the content and/or bully should be removed from the site in a timely manner.