A handful of iOS developers received letters this week from a patent holding firm claiming that their applications that offer in-app purchases infringe on the firm's intellectual property (IP). The letter threatens legal action if developers don't license the patent within 21 days. Lodsys, the firm in question, has apparently patented a system that collects usage data and facilitates feedback between a customer and vendor, though it doesn't address financial transactions specifically. The allegedly infringing applications use Apple's in-app purchase tool to encourage users to upgrade to a paid version after downloading a free app. Though it's possible that Lodsys has sent a similar warning to Apple, only individual developers confirmed receiving the document. This makes us wonder if the company is skipping the well-armed big target in favor of the little guys.

Several developers posted on Twitter after receiving the letters, including Patrick McCarron (Shanghai for iPad), James Thomson (PCalc), and Matt Braun (MASH). They're understandably unwilling to share too many details at this point -- even though Apple developed the framework, developers could still be liable. Lodsys appears to be in the business of launching suits referencing U.S. patent 7,222,078, having gone after Canon, HP, Samsung, and other giants earlier this year. As the developers that have come to light so far are independent, with limited budgets, some have reached out to Apple legal for assistance, and are awaiting response. We aren't seeing the connection between the patent and in-app purchases, though that's ultimately up to a federal court to determine, if the firm even files a lawsuit. Drama in its finest form, folks.