Slave labor 

Slave labor refers to persons, especially a large group,performing labor under duress or threats, as prisoners in a concentrationcamp; a labor force of slaves or slavelike prisoners. It affects millions of men, women and children around the world. It is most often found in industries with a lot of workers and little regulation. Slavery began to exist before written history, in many cultures. A person could become enslaved from the time of their birth, capture, or purchase.