Prison labor in the United States is referred to as insourcing. Under the Work Opportunity Tax Credit (WOTC), employers receive a tax credit of $2,400 for every work-release inmate they employ as a reward for hiring “risky target groups.”

The workers are not only cheap labor, but they are considered easier to control. They also tend to be African-American males. Companies are free to avoid providing benefits like health insurance or sick days. They also don’t need to worry about unions, demands for vacation time, raises or family issues.

According to the Left Business Observer, “the federal prison industry produces 100 percent of all military helmets, war supplies and other equipment. The workers supply 98 percent of the entire market for equipment assembly services; 93 percent of paints and paintbrushes; 92 percent of stove assembly; 46 percent of body armor; 36 percent of home appliances; 30 percent of headphones/microphones/speakers; and 21 percent of office furniture. Airplane parts, medical supplies and much more: prisoners are even raising seeing-eye dogs for blind people.”

With all of that productivity, the inmates make about 90 cents to $4 a day.

Here are some of the biggest corporations to use such practices, but there are hundreds more:

Whole Foods

Since 2011, Whole Foods has benefited from inmate labor, purchasing food from Haystack Mountain Goat Dairy and Quixotic Farming ; two private vendors that uses cheap prison labor to raise fish and milk and herd goats.