Hold the iPhone —a recent lawsuit by a group of Chicago police officers should have employers on high alert—at least those who permit, officially or not, non-exempt employees to do anything business-related on a mobile device.

In this lawsuit, which recently started trial in the U.S. District Court for the Northern District of Illinois, the Chicago Police officers claim that they performed off-the-clock work by answering calls and other communications on work-issued mobile devices. While the police department says it does not permit officers to carry the mobile devices while off-duty unless specifically authorized, the officers claim there is an unwritten policy requiring them to constantly keep in contact while off-duty by answering phone calls and receiving as many as 100 emails a day.

Of course, almost everyone has a cell phone or mobile device, and most everyone uses the device for some aspect of work-related activity—even if only for a minute or two per day. Checking work schedules, advising a coworker where a file or piece of equipment is located, providing a phone number for a customer or client, or answering a quick email about the status of a project are all normal activities for today’s workforce. At what point do these activities become compensable time worked under the wage and hour laws? Does it matter if the device is employer-issued or personal? How does an employer monitor an employee’s after-hours usage? All of these questions have been quietly smoldering for years, waiting to potentially spark a new wave of employee lawsuits. What happens in Chicago in this particular case will not answer all of these questions, but it certainly has the potential to ignite an issue that could spread litigation across the employment landscape.