That might have been some fake news that worked itself into my brain. Politfact says it's mostly false [1] and that McDonald's doesn't use prison labor in its franchises but did at one point contract out the manufacturing of their uniforms to a company that used prison labor.

Although according to the ACLU [2], prisoners are used in McDonald's supply chain and in restitution centers in Mississippi (which is very different from Holmes' federal case, mind):

> Mississippi is the only state that still uses restitution centers to lock people up for an indefinite period of time while they work for private employers to earn money to pay off court-ordered debts. Hundreds of people a year are sentenced to be confined in Mississippi’s restitution centers, where they are required to stay until they pay off court fees, fines, and restitution. Workers are required to pay for room and board, transportation to their jobs, and medical care costs. They work slaughtering chickens, cutting catfish at processing plants, at Popeyes and McDonald’s franchises, and for auto mechanic shops, furniture companies, and meatpacking plants....

> ... Taylor Farms, North America’s largest supplier of salads and fresh-cut vegetables, paid over $2.2 million to Arizona’s prison industries program for labor contracts to employ incarcerated workers to cut and package fruit and vegetables for the company.371 Taylor Farms supplies some of the nation’s biggest fast food and grocery chains, including Chipotle, Costco, Kroger, McDonald’s, Pizza Hut, Ralphs, Safeway, Subway, Target, Walmart, and Whole Foods Market.

That's a hell of a list though. Costco, Kroger, Target, Walmart, and Whole Foods basically covers every consumer in the country

[1] https://www.politifact.com/factchecks/2020/jun/22/instagram-...

[2] https://www.aclu.org/wp-content/uploads/legal-documents/2022...