Patent trolling over old and fundamental technologies is not something that a lot of patent collection & enforcement firms are bold enough to do, and it seems that Personal Audio, LLC's days of doing just that with the idea of podcasting are pretty much over – the company's patent for podcast technology has been invalidated by the US Court of Appeals for the Federal Circuit. After raking in millions from fundamental patents, including famously and successfully suing Adam Corolla over his podcast, the Electronic Frontier Foundation stepped in back in 2015 and asked US courts to invalidate Personal Audio LLC's patent for a "system for disseminating media content representing episodes in a serialized sequence." While the courts initially went with it, Personal Audio, LLC appealed the decision, and that appeal has officially been lost as of today.
The podcasting patent is one of five somewhat basic patents that Personal Audio, LLC uses in court. According to the company's website, the patents were all issued in different years, but actually originate from a patent disclosure filed all the way back in 1996. The patents cover audio messaging, personalized recommendations, episodic content, and even something as basic as downloadable music playlists, a patent that Personal Audio, LLC once managed to successfully use against Apple.
Some of the patents are extremely sweeping and include diagrams and rundowns that could potentially cover a wide range of systems used by different companies. The patent pertaining to personalized recommendations, for example, is listed as a "system for electrically distributing personalized information," and a diagram included in the patent shows a basic setup with an FTP server, web page, HTML server, client, and various processing centers, which could potentially be a twist on almost any setup used by modern web firms. There has been no word thus far on the chances of invalidating any of the other patents held by this company on the grounds of them being far too sweeping, or that Personal Audio, LLC did not invent the technology behind them, which was the argument here. Still, with one of the company's patents down, it's quite feasible that the Electronic Frontier Foundation or others may see fit to go after Personal Audio, LLC's other patents.