ADAM CAROLLA, an American television and radio show host, is not famed for his moderation. He is a sometimes beloved, sometimes hated loudmouth, who shifted from working with large media outfits on shows such as the syndicated radio programme "Loveline" (co-hosted with "Dr Drew" Pinsky) and the cable TV "The Man Show" (with Jimmy Kimmel) to a self-owned podcast, "The Adam Carolla Show". His programme has consistently topped Apple's iTunes charts as the top download. It is supported through advertising. Thus it is no surprise that Mr Carolla's reaction to his company, ACE Broadcasting Network, being sued a year ago by Personal Audio, a non-practicing patentholding entity (a "patent troll"), was to speak out fiercely and at length. Personal Audio has a patent issued to it in 2012 that, according to one of its founders, James Logan, covers the production of serialised or episodic content that can be downloaded from a specific URL that client software can retrieve and store—effectively the definition of a podcast. (The precise claim in the patent is much more precise and lengthier.) Personal Audio has also filed suit against NBC and CBS, as well as Discovery Channel's HowStuffWorks.com and TogiEntertainmnet's TogiNet streaming station.

Mr Carolla has launched a campaign to raise the $1.5m his attorneys estimate the suit could cost at a minimum to defend, and is currently on a speaking tour of other podcasts to raise awareness (and funds). A benefit event is upcoming. He has raised $175,000 in a matter of weeks, and estimates $100,000 has been spent on lawyers so far. No trial date has yet been set.

While the suit does not detail a specific financial demand, Mr Carolla tells Babbage that he was asked for $3m, a sum he finds laughable based on his network's revenue (which he does not disclose). Because even a settlement would cost a significant sum to negotiate and then pay out, Mr Carolla opted to go full monty and oppose the suit entirely, while enlisting the aid of other podcasters. "They're suing me, but they're coming after you next," he tells his peers. (Your correspondent runs a wee podcast independently but has received no letters from Personal Audio.)

Patent defences are an expensive matter, and most cases are settled prior to litigation as there is little opportunity for a defendant to reclaim court costs if they prevail. Non-practicing entities typically have a war chest of funds, often won from other suits, to create an asymmetrical benefit. The firms are sometimes founded by lawyers or in a partnership with lawyers, thus providing a benefit in legal labour, too. And plaintiffs aren't required to provide a standard fee sheet to those from whom it might demand payments. Mr Logan says his firm has not yet released a schedule of fees it would propose podcasters pay. "We might have a more specific price sheet at some point in time," he says.

But the patent at the heart of Personal Audio's lawsuits is receiving acute attention as it highlights several weaknesses in both patent law and the US Patent and Trademark Office's (UPSTO) processes. First, Personal Audio fits the definition of a "patent troll", or an entity formed for the basis of prosecuting patent lawsuits and licensing without manufacturing products or services. The Obama administration has been slowly clamping down on such firms since 2011, with new rules put in place in 2013, and the reiteration of its intent to push further still in February.

Second, Personal Audio registered its operations in Marshall, Texas, the home of a subdivision of a US District Court well known for being friendly to patent plaintiffs and uninterested in allowing a shift to a more sensible or convenient venue relative to the alleged violations. Plaintiffs prevail nearly 60% of the time in the Eastern Texas venue, compared to just over 30% across all jurisdictions, according to a PricewaterhouseCoopers report. So-called non-practicing entities like Personal Audio prevail 47% of the time in the Eastern District of Texas compared with 24% of cases tried overall.

Third, the firm's podcast claim was filed in 2009. It updated an earlier 1996 patent application (8,112,504) that related to producing customised analogue cassette tapes with current news as part of a firm also called Personal Audio that Mr Logan ran at the time until its bankruptcy in 1998. The 2009 filing contained a description of podcasting as an outcome of the main portion of the patent, which remained unchanged. This is purely legal, though a number of rules have changed since 2001. Because the application was filed in 1996, the patent will expire in 2016, and Mr Logan says his firm may only address alleged violations starting in 2012, the year it was granted.

Finally, the issue of prior art comes into play, in which a patent must be original at the time it is applied for in the context of other patents and other work in the field. A patent examiner is supposed to consult extensively, but the USPTO has consistently fallen flat. (The Obama administration proposes more crowdsourcing of prior art to assist in this aspect.)

The Electronic Frontier Foundation (EFF) has come in on the matter of prior art, by fundraising tens of thousands of dollar to file an "inter partes review" or re-examination by the USPTO. EFF has much art prior to the 1996 application; that date is when the clock was set even though the additional claim was filed in 2009.

EFF's Daniel Nazer, a staff attorney, says the organisation became involved because of its concerns relating to the dissemination of free speech online. Mr Nazer says, "It occurred to them in 2009 that they invented podcasting." The EFF has "submitted some prior art and are arguing that the patent is anticipated and obvious on the basis of that prior art." The patent office's appeals board will determine by May 2014 whether to initiate a review which would take a year or more to complete. (In a sideshow to the main affair, Personal Audio attempted to subpoena EFF to obtain a list of donors to the re-examination campaign, claiming that if any defendant had contributed, it would constitute double-dipping under inter partes review regulations. EFF objected on First Amendment grounds; a judge found in EFF's favour because the review hasn't yet concluded, and thus there's no basis on which to make the claim.)

Mr Carolla cultivates a laddish persona, but appreciates EFF's efforts and has developed an unwanted expertise in patent issues, even as he defers to his lawyers (on his side "for now", he notes). He reckons his case may just be one of many involving Personal Audio. "They'll just find the top 100 most popular podcasts on iTunes. They'll start with me and just work down the line," he says.

Mr Logan, for his part, notes that his ideas were embodied in a product and company in the late 1990s that failed. "We feel that we are deserving of the rewards from having spent all that time and money back then inventing that stuff and patenting it," he says. It will be some time yet before the USPTO and a jury decide if they agree with Mr Logan in this matter or not.