Cameron and Tyler Winklevoss, the 29-year-old twin Harvard graduates, Olympic rowers and multimillionaire entrepreneurs, make no secret of their belief that Facebook founder and former colleague Mark Zuckerberg swindled them out of a fortune.
Despite taking a reported $65 million from the billionaire in a 2008 legal settlement, the twins are chasing a bigger legal payout from a partnership they say they forged with Facebook's "toddler CEO" when the three were students at Harvard.
In a recent interview with CBS' "60 Minutes," the twins said Zuckerberg was their "teammate" and "partner" who betrayed them.
"I'm not sure anybody can quite put themselves in our shoes and understand what it must have felt like to start an idea in 2002, to approach a fellow student in 2004, to have it stolen, sabotaged, ripped off," one of the Winklevoss brothers said in the interview.
But Wayne Chang said he knows exactly what it feels like to be cheated by a partner, because, he said, the Winklevoss brothers did the same to him.
"They pretty much treated me the way they say Facebook treated them," said the 27-year-old entrepreneur. "I got backstabbed."
Last December, in a complaint filed with the Superior Court in Suffolk, Mass., Chang claimed he is owed a part of the Winklevoss' settlement money from Facebook because his Web company had merged with the brothers' social network ConnectU to create the Winklevoss Chang Group.
And he's going after a piece of the $65 million. Chang said because the Facebook litigation was a shared asset of the company, he said he is entitled to a piece of the Facebook settlement.
The Winklevosses filed a motion to dismiss the complaint, which Chang has formally opposed. A January hearing is scheduled regarding the motion to dismiss, Chang said.
"I just want what was rightfully mine," he said. "I just want to go for my share of the company, my share of the partnership."
In addition to naming the Winklevoss brothers, Chang's suit names their father, Howard Winklevoss; Divya Narender, another ConnectU partner; ConnectU Inc. and the law firm that represented them in the suit against Facebook, Finnegan, Henderson, Farabow, Garrett & Dunner LLP.
He sues the Winklevosses and Narender for a number of claims, including breach of contract, breach of partnership and breach of covenant of good faith and fair dealing.
Lawyers for the Winklevosses and Narender did not respond to phone calls from ABCNews.com Friday afternoon and Monday morning asking for comment.
Finnegan, Henderson, Farabow, Garrett & Dunner LLP declined to comment for this story.
Chang said he first teamed up with the Winklevoss brothers in 2004, after a file-sharing network he started as a student at the University of Massachusetts Amherst spread to dozens of college campuses across the country, grabbing headlines along the way.
In November 2004, Chang said, after the Winklevosses had already started their litigation with Facebook, he and the brothers created a Memorandum of Understanding (MOU) that joined his network i2hub with the Winklevoss' ConnectU.
The MOU said Chang would receive 15 percent of ConnectU after the integration.