Uniloc USA Inc., an accused patent troll best known for winning a nearly $400 million verdict against Microsoft Corp. in 2009, is looking for more returns from its most prized IP asset.

Uniloc launched its latest litigation campaign this week in East Texas federal district court, suing 16 defendants including Canon USA Inc., Juniper Networks Inc. and ArcSoft Inc. The complaints, filed on Tuesday, claim the companies infringed Uniloc’s patent for a “system for software registration” by making and selling product registration and activation systems meant to reduce software piracy.