How do I get someone with over 20 profiles banned?

This person is attacking me by Answering questions completly wrong then voting for themself up to 20 votes, (usually last minute) or finds my answers and votes "No best answer", and multiple thumbs down. Reports my perfectly good answers as harmful, getting them removed. I'm tired of it! I report it everytime, but still he/she continues. How do I get this to stop. I enjoy Yahoo Answers and would like to continue. But I need your help in bringing this monster reign of terror to an end.

I know of his other profiles, and have blocked as many as I can but he creates more every day. I don't want to make my profile private either.