Mark Zuckerberg, everyone’s favorite Web 2.0 child prodigy, is being confronted with intellectual property-theft accusations, coming from his former employers from 2003.

Back then, Zuckerberg apparently did some coding work for the founders of Facebook’s rivaling social network called ConnectU, whose principles of functioning are similar to Zuckerberg’s site.

Cameron and Tyler Winklevoss, and their business partner Divya Narendra, are accusing Zuckerberg of stealing proprietary code from ConnectU and of later integrating that code as an original idea in Facebook.

Cameron and Tyler Winklevoss were the same year as Zuckerberg at Harvard when the alleged theft was committed. The latter worked in November 2003 for the two brothers, doing coding, sending e-mails and attending meetings, but soon left ConnectU (which at that time bore the name Harvard Connect) to launch his personal site, three months later. Facebook is now one of the most important destinations for young people all over the world and its investors are considering a sale offer only if the price goes beyond $10 billion. As to further fuel rumors about a possible stock listing, Facebook jired YouTube’s former finance chief Gideon Yu to be its CFO and has also advertised for a stock administrator. It currently boasts with more than 30 million users, while ConnectU has only 100,000.

Mr Zuckerberg has admitted that he did six hours of coding for ConnectU on a voluntary basis, but said that he thought the site was a "personals page" and not a social networking site.

Mr Winklevoss disagreed: "It was clear to him what we wanted. He stalled us for months while he worked on his own idea, which he launched in February as an original idea."

The Winklevoss brothers are asking the court to shut down Zuckerberg’s site and redirect all profits to them. They are accusing their former employee of copyright infringement, misappropriation of trade secrets, and breach of contract. In a response to ConnectU's claims, Facebook's lawyers, Orrick, Herrington & Sutcliff, said: "Only one of the students had an idea significant enough to build a great company. That person was Mark Zuckerberg."

Although some might accuse the Winklevosses of opportunism, their claims are not something new. The first suit was filed back in August 2004, when Facebook had about 200,000 users, but was dismissed early this year due to a procedure defect. However, since the substance of the initial trial remained untouched, the two brothers filed another suit and the defendants are expected to appear before Judge Douglas Woodlock in Boston federal court on Wednesday.

In May this year at F8 conference, Facebook announced Facebook Platform, a new development platform that enables companies and engineers to integrate with the Facebook website and gain access to millions of users.