Mark Zuckerberg might want to fast-track Facebook's initial public offering.

In what appeared to be a hasty response to the launch of Google's rival social-networking product, called Google+, Mr. Zuckerberg on Wednesday unveiled Facebook's new video-chatting feature. He called it "super awesome." Too bad Google made the same feature available in 2008. Indeed, Facebook suddenly looks vulnerable. This could be bad news for investors who have recently paid top dollar for stock in Facebook in private sales.

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