What employee off-duty conduct can employers regulate in the age of COVID and protests?

Can employers make employees quarantine for two weeks before returning to work if they've attended a protest of more than 150 people? "Enforcement truly can be fraught with peril," says Ron Holland of McDermott Will & Emery. (Credit: Brian Goff/Shutterstock.com)

Here's a hypothetical: You run an essential business in Naperville, Illinois, a city currently in Phase 4 of COVID reopening that bans gatherings of more than 50 people. Iowa allows large gatherings with no restrictions. It gets brought to your attention that John Smith, one of your employees, attended a political protest in Iowa over the weekend with 150 other people. John is set to return to work on Tuesday. Do you make John quarantine for two weeks before returning to work?