Since Ceglia began raising his legal claims to ownership in June 2010, Facebook has been dismissing them as frivolous, or worse. Last week, it filed a the lawsuit claiming it's nothing more than a "fraudulent shakedown."

In its motion, Facebook declares "Ceglia, a career criminal and hustler, has perpetrated a massive fraud on the federal courts and Facebook."

Needless to say, that's not the view of the case taken by Milberg.

"We took a good hard look at all of the information available, including evidence in Mr. Ceglia's favor, and we believe he deserves to have his day in court," Dumain declared when Milberg announced its intention to enter the fray.

"It should be up to a jury to weigh the contradictory claims, including evidence that supports Mr. Ceglia’s case, such as his email correspondence with Mr. Zuckerberg and experts' testimony about the authenticity of the contract," Dumain added.