Amazon's warehouse workers won't be able to collect pay for the after-hours time they spend in security checks according to a unanimous decision handed down from the US Supreme Court today. The screenings, which companies like Amazon use to quell employee theft, can take up to 25 minutes according to the lawsuit originally filed in 2010.

Though Amazon is at the forefront of the decision, the original lawsuit was filed against Integrity Staffing Solutions, a company that provides staffing and warehouse space to the online retailer. The plaintiffs argued that failing to compensate employees for the mandatory checks violated the Fair Labor Standards Act (FLSA), specifically referencing the requirement to remove things like belts and keys to pass through metal detectors and the amount of time that made the screenings last. They sought double damages, back pay, and overtime as compensation.

The case decided on today was accepted by the Supreme Court for argument back in March after it had been allowed to move forward by the US Court of Appeals for the 9th Circuit in April of 2013. That court's decision stated that "the security clearances are necessary to employees’ primary work as warehouse employees," which is where the Supreme Court disagreed. The official opinion from the Supreme Court states that the "primary work" the FLSA is concerned with only involves the tasks that workers were employed to perform, and therefore anything else is non-compensable.

That part of the decision is essentially the argument that Integrity originally made in its brief to the Supreme Court back in April, which claimed that these security checks are no different from other required tasks that happen off the clock:

Security screenings are indistinguishable from many other tasks that have been found non-compensable under the FLSA, such as waiting to punch in and out on the time clock, walking from the parking lot to the work place, waiting to pick up a paycheck, or waiting to pick up protective gear before donning it for a work shift.

Attorneys for the plaintiffs told Bloomberg in October that if they had won the appeal, Amazon and staffing agencies like Integrity "could be required to pay as many as 400,000 workers back wages amounting to $100 million or more."