• by Gavin O'Malley , Staff Writer @mp_gavin, April 3, 2012

Long a lightning rod for controversy, life as a public company is proving no less tumultuous for Groupon. News broke this week that the company is being investigated by the Securities and Exchange Commission, which sent its stock sloping by more than 15%.

“The regulator's probe into the popular online-coupon company is at a preliminary stage, and the SEC hasn't yet decided whether to launch a formal investigation into the matter,” The Wall Street Journal reports, citing a source.

As VentureBeat points out, Groupon’s stock has been falling since it revealed on Friday that it was revising its first quarter earnings to reflect a larger-thatn-expected loss. “With its spotty accounting history, Groupon is now a juicy target for securities lawyers representing investors, who believe the company may be liable for the losses their clients have suffered since Friday,” it writes.

When Groupon first reported its earnings, it had reported a 194% increase at $506.5 million. “With the revisions, operating expenses were increased, reducing the company’s operating income by $30 million and its net income by $22.6 million,” notes WebProNews.

“The daily deals site said in a regulatory filing … that it had discovered ‘material weakness’ in internal controls over its financial statement and that its fourth-quarter results were worse than previously stated because of higher refunds to merchants,” CNet reports.

“Rocky Agarwal has to be feeling pretty vindicated right about now,” writes GigaOm. “He has been blogging about Groupon and its business model, screaming that it has more holes than swiss cheese for almost 18 months.”

“This could all blow over and turn out to be no big deal,” Business Insider reasons. “But drawing the attention of the SEC is never a good thing. Especially when Groupon had to amend its IPO filing twice after the SEC complained.”

Indeed, as The Resister writes: “The commission has already had to step in with Groupon before its stocks went live, when its initial public offering prospectus listed a controversial accounting metric that the SEC asked the firm to remove.”