New York - Facebook's stock has fallen below $30 for the first time.The stock fell $2.01, or 6.3%, to $29.90 in midday trading Tuesday. That's down 21% since its much-awaited public stock debut this month. It went as low as $29.65.Facebook Inc. began trading publicly on May 18 following one of the most anticipated stock offerings in history. The initial public offering of stock priced at $38 a day earlier.But the launch from far from smooth. The stock's public debut was marred by technical glitches at the Nasdaq Stock Market that delayed trading. And the company, along with the investment banks that led the IPO, is the subject of shareholder lawsuits. Facebook says the lawsuits are without merit.