I had a coworker who sued our employer (after he was laid off) for unpaid labor and he was a well-paid employee. They settled with a pretty big check. We were expected to work at least 5 hours of unpaid time each week and many worked much more. Be advised, there are time limits on collecting back pay even if there is malfeasance on the part of the employer. It is important to have records and proof that the unpaid labor is demanded, less than voluntary.