Bellevue-based Intellectual Ventures, the patent holding firm run by Nathan Myhrvold, has sued AT&T, Sprint, and T-Mobile, as it continues to exercise its patent muscle in the courts. IV said Thursday that it has attempted to discuss licensing options with each of the firms, but that none were responsive to its efforts. The lawsuit was filed in the U.S. District Court of Delaware. In the lawsuit, Intellectual Ventures listed 14 different patents from a myriad of different inventors--and including patents on sending URLs in email, sending SMS messages, and more--which it says the firms are in violation of. The lawsuit comes as Intellectual Ventures has begun a campaign of actively pursuing companies in court from its vast trove of patents; the firm had amassed a patent portfolio over the last few years, but had not been aggressively pursuing companies for licensing fees. Unlike a number of smaller, but more aggressive patent licensing firms, Intellectual Ventures has gone straight to the major technology companies in its suits, as opposed to throwing its patents at many smaller, less legally equipped companies.