Earlier this decade, Lexmark filed a similar lawsuit against a manufacturer of a chip that allowed third party cartridge makers to have their products work on Lexmark printers as well as printers from other manufacturers. Lexmark invoked the DMCA in this case, but eventually lost the case in June 2005.
This time around, the company's taking a different approach, claiming that a whopping 24 companies are "engaged in the manufacture, importation and sale of replacement cartridges for various Lexmark laser printers and multifunction devices", and thereby violating at least 15 of Lexmark's patents.
Lexmark is being totally hip by filing this lawsuit in two ways. First, they request that the United States International Trade Commission bans import of the affected products. Second, they filed a patent infringement suit US District Court for the Southern District of Ohio, seeking injunctive relief, monetary damages and attorneys' fees.