[nomid]

Some info here: https://www.latimes.com/business/hiltzik/la-fi-hiltzik-mark-... but the gist of how he controls it is pretty simple:

"Zuckerberg owns or controls 88.1% of Facebook’s Class B shares, which each have 10 votes at the annual meeting — 3.98 billion votes overall. There are only 2.4 billion Class A shares, which are the only shares ordinary investors can buy. So any proposal Zuckerberg doesn’t like will fail by nearly a 2-1 margin, assuming all Class A investors vote together, which never happens. (Zuckerberg owns 0.5% of the Class A shares.)"

Clearly all throughout the funding rounds he made sure he controlled the shares that mattered.