Yahoo's claim that Facebook filed some of its patents fraudulently has come back to bite it as Facebook's lawyers not only prove that the patent is legit, but also that no one has ever thought to actually check the available records until now.

It's embarrassment all round, as Yahoo alleged that a sworn declaration that should have existed didn't exist. But it does exist.

As patent dispute expert Florian Mueller succinctly puts it, "Yahoo's lawyers alleged deception when they simply failed to do their job. Facebook obtained the record and provided it to the court, and in the process found out that nobody had even accessed (!) the record before."

This article probably doesn't exist

You may recall that Yahoo reckons it actually came up with the basic idea behind Facebook and patented it back when a face book was just a book full of portraits and not the multi-billion dollar social network we know and sometimes love today.

The patents in question today relate to systems for 'controlled distribution of user profiles over a network'. It was actually a guy named Chris Chea who invented the system – or at least filed the patent for it – and Yahoo says his patent is invalid because a second inventor, Joseph Liauw, was named in a first document but left out of a second.

Apparently Liauw was named in error, which Yahoo latched on to and said the only way he should have been dropped from that second document is with a signed affidavit saying he was erroneously included in the first place, otherwise the patent is invalid.

Unfortunately for some researcher at Yahoo's law firm, the affidavit was procured and included back in 2001 – a fact that didn't come to light until after Yahoo said that Facebook had been "false and deceptive because no Oath or Declaration by Mr Liauw was ever submitted."

And why didn't it come to light? Because no one at Yahoo ever thought to look; Facebook's lawyers note that no other request for access to the relevant file had been made when they went looking for the affidavit themselves.

So, basically, it's a storm in a teacup because Yahoo didn't do its research properly. What an embarrassing development in a patent dispute that many already saw as embarrassing for Yahoo in the first place.

From Foss Patents