Possible Clues:

• Took action, in a sense
• Like a defendant in court
• Didn't accept an apology, maybe
• Made a case?
• Like patent infringers, often
• Like a malfeasant, often
• Dragged into court
• Fall Out Boy "Our Lawyer Made Us Change the Name of This Song So We Wouldn't Get ___"
• Started proceedings against (someone)
• Sought restitution legally