Motorola has filed a complaint over RIM's BlackBerry range, claiming they infringe a number of patents it holds.
The case has been filed with the International Trade Commission in the US, and Moto is looking to block RIM from importing what it calls 'infringing products'.
The patents relate to Wi-Fi access, application and power management, and even the UI - which would be strange given Motorola's clunky interface, but we assume there must be some good elements it believes RIM has nabbed.
The litigation is ongoing, but Motorola believes there time has come to bring things out into the open, as it looks to be re-born through a slew of Android phones as well as protecting the valuable assets it created when it was involved in the development of the mobile phone.
Jonathan Meyer, Senior Vice President of Intellectual Property Law at Motorola, stated: "Through its early-stage development of the cellular industry and billions of dollars spent on research and development, Motorola has created an industry-leading intellectual property portfolio that is respected by the entire telecommunications industry.
"In light of RIM's continued unlicensed use of Motorola's patents, RIM's use of delay tactics in our current patent litigation, and RIM's refusal to design out Motorola's proprietary technology, Motorola had no choice but to file a complaint with the ITC to halt RIM's continued infringement.
"Motorola will continue to take all necessary steps to protect its R&D and intellectual property, which are critical to the Company's business."