NEW YORK ( TheStreet) -- The investment in Facebook by Goldman Sachs ( GS) is prompting the Securities and Exchange Commission to reexamine the rules separating public and private companies, The Wall Street Journal reported Wednesday. U.S. securities laws currently require public financial disclosures for companies with at least 500 investors, but though some believe Facebook has far more than that already, with the number expected to grow, legal maneuvering has allowed Facebook and other companies to avoid opening up their books. The Journal cited an anonymous source "familiar with" Facebook, who said the company had less than 500 investors at the end of last year, though it also cited a post on Facebook by Salesforce.com ( CRM)chief executive Marc Benioff saying Facebook already has "thousands of investors." Goldman and Russian firm Digital Sky Technologies together took a $500 million stake in Facebook, in a deal structured so that Goldman can parcel out its stake to wealthy clients while officially being classified as just one investor, according to the Journal and other reports. With more private internet companies expected to use Goldman's Facebook deal as a model, the SEC is looking at whether it needs to rewrite the rules, the Journal reported, stating "the review is at an early stage." Among those companies is Groupon, an email coupon company that spurned a $6 billion buyout offer from Google ( GOOG), the Journal reported last month. -- Written by Dan Freed in New York.