At issue is whether employers should compensate employees for required activities conducted before and/or after the clock's been punched. According to a 1947 Supreme Court decision, only pre- and post-shift activities that were "integral and indispensible" parts of the job required compensation.

The plaintiffs claimed they were forced to spent as much as a half an hour per search, time that really added up over a year of labor. Amazon begged to differ with the workers' estimates of how much time the searches cost them.

"The allegations in this case were simply not true — data shows that employees typically walk through security with little or no wait, and Amazon has a global process that is designed to ensure the time employees spend waiting in security is less than 90 seconds," Amazon spokeswoman Kelly Cheeseman said.

But some pre- and post-shift activities do meet the standard of "integral and indispensible." Examples routinely cited: meat packers who had to sharpen their knives outside of work hours, and battery makers who had to change clothes and shower after work to rid themselves of toxic chemicals.

But a quick pat-down to ensure Amazon's warehouse employees weren't stealing didn't meet the standard, the court ruled. Even if workers had to stand in line for up to a half hour while the pat-downs took place, the 1947 precedent wasn't met, SCOTUS ruled.

Two weeks later, Apple employees learned their legal complaint against the searches had been dismissed.

The Apple case had gone to the U.S. District Court, Northern District of California, where Judge William Alsup ruled the Amazon decision essentially gutted the plaintiffs' arguments.

Several different Apple employees had challenged Apple's refusal to compensate them for time spent in searches. Alsup consolidated the cases and then dismissed them. No class had been certified in the Apple case, which Alsup noted in his brief order.

He gave the plaintiffs until Jan. 6, to file a motion to submit an amended complaint that would outline why some of the Apple employee claims should survive the Amazon decision.

The Apple situation was somewhat difference from Amazon's. Apple employees had to undergo backpack and other personal bag checks before their lunch breaks and after their shifts ended, Apple's effort to reduce "shrinkage," that time-honored retail term that serves as an alternative to "theft."

"Plaintiffs offered the example of one worker who racked up anywhere from 50 minutes to 90 minutes of uncompensated overtime, which equated to about $1,400 over the course of one year" owing to such searches, the online news source appleinsider.com reported.

The Amazon ruling is bound to impact employee challenges to similar security measures take by companies like CVS Pharmacy and TJX Cos., parent of TJ Maxx, the apparel and home fashion retailer.

"The Amazon decision will have far-reaching impact on other litigation," said an article on the National Law Review's website. "Approximately 13 class action lawsuits have been filed against Amazon and other companies involving more than 400,000 plaintiffs with hundreds of millions of dollars at stake."

That doesn't necessarily mean employers are off scot-free from having to compensate workers for security clearance requirements. Michael Reilly, director of the labor and employment practice group at Lane Powell law firm in Seattle, told The news source hreonline.com that state laws requiring such compensation would prevail over the SCOTUS ruling.

"Employers have to follow the statute that provides the most benefit to the employee," he said.