If you need some moderators I volunteer. 🙂
Or move to another Forum provider, with better software, where multiple threads on same subject can be merged; multiple logins from same IP address can be monitored and stopped earlier etc.
I know one forum that blocks any Gmail, Hotmail, Yahoo address as anyone can set these up. Stipulating a work address (which could remain hidden if privacy was a concern) might make people think twice before posting?