Redstone, Murdoch Fall in Forbes Rankings

Forbes released its billionaire's list tonight, and not surprisingly, a number of top media executives have seen their rankings tumble.

Viacom chairman Sumner Redstone's net worth has dropped from $5.1 billion to only $1 billion while News Corp's Rupert Murdoch has fallen from $6.8 billion to $4 billion.

Liberty Media's John Malone saw his own net worth go from $2.3 billion to $1.5 billion. Oprah Winfrey, meanwhile, remains on par with last year, at $2.7 billion.

Topping the list, once again, is Bill Gates, who lost $18 billion over the past year, according to Forbes. His net worth is $40 billion. Facebook founder Mark Zuckerberg no longer makes the list.

New York City Mayor Michael Bloomberg is the only member of the top 20 whose net worth has increased, thanks to a new valuation of his business news empire. The Mayor bought a 20% stake in Bloomberg back from Merrill Lynch for $4.5 billion in the summer of 2008. At the time the company was valued at $22.5 billion, and Bloomberg's own stake at $15 billion.

According to Forbes, California is home to the most U.S. billionaires: 77 live there while New York is home to 64 of the world's richest people.