The theory Felix Salmon tries to expound upon is the following:
1. Mark Zuckerberg decides he wants to, say, control all media.
2. He issues a bunch of nonvoting Facebook stock and buys media companies with it.
3. Although common stock holders are diluted, Zuckerberg doesn't care and retains total control of Facebook.
4. Repeat until Mark Zuckerberg controls the world.
How far towards world domination can Zuckerberg proceed?
Facebook is worth $344 billion, with 2.3B shares. Disney has a market cap of $174 billion. If Zuckerberg wants to buy Disney, he needs to offer, say a 30% premium or $226 billion. That means post-merger the combined company should be worth about $54b less, or $466 billion.
Can Zuckerberg then rinse and repeat? At what point does everybody sell their nonvoting shares, leading to a valuation of $0 instead? Or does Facebook stock retain enough value to literally buy everything?