From CNET in Patent scare hits streaming industry:
a company called Acacia Media Technologies, said it owned patents on the process of transmitting compressed audio or video online, one of the most basic multimedia technologies on the Net.
From the article it's nor clear whether the claim has serious IP ground, but this new patent threat is following the same exact pattern as SBC and others: go after the little fishes that can't fight and will have to pay a license because it's cheaper than litigation, and get enough of them to convince bigger pockets that they should follow suit.
The article outlines that all patents can be challenged, that broad patents have been thrown out in court and that "legal teams on the defense often spend considerably more time than the overworked United States Patent and Trademark Office in researching possible previous inventions that would invalidate a patent." This yet another sign of the failure of the patent office at doing its job and letting others clean the mess.