Should a good person, take revenge on a bad?

My last employer, who lured me away from a steady job, laid me off when things began to go downhill, just in time so he wouldn't have to pay unemployment. He never paid my tax deduction payroll taxes and never sent me a W-2. He is now employing the "unemployed" by paying them a small cash wage under the table. Should I report him? If I do, most of his employees would get in trouble as well....