Twitter is going public. The social media heavyweight tweeted Thursday that it had just filed documentation with the Securities and Exchange Commission for an initial public offering of stock, setting in motion the process of taking the company public. "We’ve confidentially submitted an S-1 to the SEC for a planned IPO. This Tweet does not constitute an offer of any securities for sale," the company tweeted from its verified Twitter account. Afterward, it tweeted: "Now, back to work," accompanied by a photo of its offices.
