Peter, if you are reading this, there's one question I'd love to ask. Why did tou even buy Facebook shares in the first place? Just to say you owned a part of Facebook? It was a clear failure from the beginning when they hit the market, way overpriced - surely you must of known this too. And then comes why other question. Why sell now, after loosing so much money? If you were willing to take a gamble in the first place, you should of been prepared to stick with it for a few years - it might go back up, but that's only if FB manage to get their shit together.
Did you even skim read the article? He invested $500k as one of their earliest investors, and turned that into $400 million. He sold when he did because of a lock up period.