I'm glad this is being brought to light... and that investors are angry. This sort of action I think should be wildly illegal.
It's removing a great deal of value from one's share. That value is being able to vote. I'm not a FB shareholder but if they had removed my voting power (or rather made it a 1/3 of what it was) I'd want compensation and then I'd sell my shares.
This sort of crap is propagating a big issue: the separation of management and control from ownership of companies. It invites irresponsibility and selfishness because the cost of such to management is continuously decreasing. While the owners (shareholders) are the ones to pay the real price for their actions.
This is how we have problems like CEOs losing money quarter after quarter but still getting bonuses and ever larger golden parachutes...
It's easy to say he's a "visionary" now but the markets facebook has ridden its growth on were not a result of it being amazing. It was a combination of the right time, luck, and a bit of vision (he does deserve some credit). Now that markets are saturated we'll see how truly visionary he is... acquiring for growth targets doesn't make him visionary it just makes him a good business person. If he can't grow it or his vision is off-- it won't matter, if he missteps and costs his shareholders. He and his cronies will still be rich as hell and his shareholders will pay the price.