An anonymous reader writes: IBM is pushing big internet companies to pay patent licensing fees in part because IBM invented the Prodigy service, a precursor to the modern web. Yesterday, Big Blue filed a lawsuit against Groupon, saying the company has infringed four IBM patents, including patents 5,796,967 and 7,072,849. IBM inventors working on Prodigy "developed novel methods for presenting applications and advertisements," and "the technological innovations embodied in these patents are fundamental to the efficient communication of internet content," according to the company. The Prodigy patents were filed in 1993 and 1996, but they have "priority dates" stretching back to 1988. "Despite IBM's repeated attempts to negotiate, Groupon refuses to take a license but continues to use IBM's property," IBM lawyers write. IBM says it informed Groupon that it was infringing the '967, '849, and '346 patents as early as 2011. As for the '601 patent, IBM says that Groupon should have been on notice of that once Priceline got sued last year.