Paul Ceglia has been trying to convince courts in the US that he is entitled to half of Facebook for nearly three years, but a judge has now thrown his key evidence out of court.
He's been dogging Zuckerberg through the courts in pursuit of the 50 per cent of Facebook and its sizable mountain of cash that he thinks is rightfully his using a contract signed by Zuck as evidence.
But its bad news for Ceglia as Judge Leslie Foschio has branded Ceglia's contract a "recently created fabrication".
Facebook is being a little less generous, with the company's deputy general counsel Colin Stretch calling the lawsuit "an inexcusable fraud based on forged documents".
The lawsuit has been rumbling on for around three years, with Ceglia contending that he and Zuckerberg signed a contract while at Harvard which split the then unnamed Facebook company 50/50.
Facebook says there was a contract, but that it was nothing to do with the product that ended up being known as Facebook.
The judge's lengthy decision took in chemical, handwriting and printing analysis on the contract to try and determine its authenticity, with the investigators concluding that it all seemed pretty dodgy.
However, not one to be knocked by setbacks, Ceglia's lawyers say he may yet appeal. He's really gunning for that The Social Network sequel, isn't he?