The difference is that those companies typically can trust that their employees will tell them the truth about where they're living. Facebook has set up pervers

The difference is that those companies typically can trust that their employees will tell them the truth about where they're living. Facebook has set up perverse incentives given that disclosing your actual location might end up dropping your salary; that means that an employee might end up being taxed incorrectly because they don't want to disclose their location.