BlackBerry has added Twitter (2:19-cv-01444) to the litigation campaign that it launched in July 2016, having already hit Avaya, BLU Products, Facebook, Nokia, and Snap to date. While the campaign has seen many more patents asserted, this latest complaint accuses Twitter of infringing six, generally related to various subject matters, including mobile devices, messaging services, and related networking equipment, through the provision of a variety of features of Twitter Ads and the Twitter app. The campaign has also seen Alphabet (Google) challenge several BlackBerry patents in inter partes review (IPR) proceedings before the Patent Trial and Appeal Board (PTAB), with mixed results, some of which each party has subsequently appealed to the Federal Circuit.