Advanced Audio began its litigation campaign almost a decade ago and is still filing new cases. The most recent suit, against Pantech, asserts five patents that the entity has used in other cases. The patents-in-suit relate to various aspects of a digital music player, including storing and playing digital music tracks (6,587,403, 7,289,393, 7,817,502, 7,933,171, 8,400,888). The entity developed the patented technology as an operating company selling custom CD-recording devices, but it began asserting its patents in litigation in 2005 and its product sales appear largely inactive. Pantech’s digital audio player products are accused of infringing the patents-in-suit, similar to other products at issue in the campaign. Most of Advanced Audio’s previous suits are now closed. Previous suits targeted Amazon, HTC, Kyocera, Philips, and Toshiba. 3/28, Northern District of Illinois, 1:14cv02211