Even with momentous issues like same-sex marriage swirling around them, U.S. Supreme Court justices seemed to relish sinking their teeth into a case asking them to define when a Fair Labor Standards Act lawsuit can be deemed moot.

The issue in Genesis HealthCare v. Symczyk, while technical, drew wide interest from business and consumer groups worried that the court’s resolution of the case will either promote or stifle collective and class litigation.