NTP filed lawsuits against Apple, Google, HTC, LG Electronics, Microsoft and Motorola in the US District Court for the Eastern District of Virginia for infringing eight of its patents related to the delivery of electronic mail over wireless communications systems. NTP is best known for its long litigation and eventual settlement with RIM, maker of BlackBerry devices. In that litigation, all the claims asserted at trial were found to be valid and willfully infringed by RIM, and the verdict was ultimately affirmed on appeal by the US Court of Appeals for the Federal Circuit. Spurred by that litigation, the US Patent and Trademark Office (USPTO) moved to re-examine NTP’s patents. In December 2009, in spite of the massive effort by the USPTO to overturn NTP’s patents, the USPTO Board of Patent Appeals ruled that 67 of NTP’s patent claims in four patents are valid, including three claims that RIM was found to have infringed. Infringement of a single claim is all that is needed for a patent to be deemed violated. NTP has also filed an appeal to the US Court of Appeals for the Federal Circuit to overturn the USPTO’s remaining rejections of NTP’s patent claims.