People like this deserve to be harassed for eternity. Pay people you don't know to threaten him in public places. I am not advising you to break the law, just be creative and there is not enough laws to protect him. Hire private detectives to follow him and create doubt in his wifes mind that he is cheating. Send hookers and pizza to his house. Prank phone calls at 3:00 am. Fling feces at his front windows. the list goes on....Make his life miserable.