I don’t believe this is true. If an Icahn-like activist investor shorted FB and successfully triggered a mass sell off tanking FB stock, it would be really hard for Zuckerberg to survive that pressure, and he’d be financially incentivized not to. You’re right in that the board doesn’t have the power to oust him, but collective investor action could. It’s hard to find people who want to rattle one of the most consistently performing tech stocks, though. Unfortunately, I think the chance of something like this happening is nil.