"Even after the IPO, Zuckerberg remains Facebook's single largest shareholder, with 503.6 million shares. And he controls the company with 56 percent of its voting stock." (http://www.msnbc.msn.com/id/47491836/ns/business/)
Does anyone know what sort of recourse the minority shareholders and the other 44% voting holders have if Mark runs the company into the ground?
Given how long such lawsuits take, it will of course be too late by then.
It still occurs with unsurprising regularity. Lots of interesting books out there which talk about why.