The charitable foundation/LLC structure that Zuckerberg and Chan have set up to give 99% of their Facebook shares was criticized a few years ago when eBay founder started one.
"Remember when Pierre Omidyar was seen as an odd duck in the philanthropy world?
"People used to scratch their heads, wondering just what the heck this eBay billionaire was up to as he and his wife Pam melded traditional grantmaking with for-profit investments. Omidyar was routinely referred to as a “philanthropist” who ran a “foundation,” but that’s not how he saw himself. Sure, his Omidyar Network, created in 2004, included a nonprofit foundation, but it also had an LLC—and, boy, did that throw people for a loop. It was hard even to find a term to describe the Omidyar Network. What was this thing?"--David Callahan, Inside Philanthropy