Reid Hoffman is … to an extent.
LinkedIn boss poised for $600m payout from sale of shares – Business – The Observer
“The serial entrepreneur seems to be behind nearly every social media firm now heading to market. He founded LinkedIn eight years ago and owns 20% of the company. Hoffman’s cash helped start Facebook, Zynga and Flickr. In 2009, he joined venture capital firm Greylock Partners where he has led investments in Groupon, among others. Twitter was about the only major social media pie in which he didn’t have a finger. But, in 2009, Twitter bought a geo-location business called Mixer Labs, funded by Hoffman, and he got shares in that too.”