Zynga files paperwork for IPO

The creator of "FarmVille" and other online games on Facebook is the latest in a series of hot social media companies to seek capital in the public market. Zynga said it hopes to raise up to $1 bil with the offering. It didn't specify the number of shares it plans to sell or give an expected price range. Watchers estimate the company's IPO could raise $1.5 bil-$2 bil and value it at $15 bil-$20 bil.