Franz Conrad von Hötzendorf was an Austrian-Hungarian general who, more than anyone else, was responsible for starting World War 1. He pushed for invading Serbia, because he thought it was necessary to save the Habsburg Empire from... something; I'm not even sure he knew exactly what. Unfortunately, he was one of the most prolifically incompetent generals of the war; and his decisions led to the deaths of millions.
What happened to him? Well, after the war, he retired; refusing to accept even the tinniest responsibility for what he had done. Decades after his death, he even somehow managed to be considered a military genius, up until people finally started to notice in the 60s that almost every single one of his "strategies" ended in failure.
What brought this up? If a man like that, can survive with his reputation intact for so long after his death, never having been punished for the horrors he caused; what hope is there that some celebrity will be punished for spreading lies about someone? The answer is simple; there is none. The evil thrive with ease, while the good must struggle to survive.