New trouble for hometown giant Groupon, this time self-inflicted. According to a report in The New York Times, Groupon chief executive Andrew Mason may have broken SEC rules preventing a company from attempting to "condition the market by hyping its stock" by issuing an internal memo recently. In it, he defends against media reports about the company's numbers, a balance sheet that will no doubt be adversely affected if Groupon's IPO is put on hold.