From the link:
Sweatshops and human trafficking: Toyota’s parts supply chain is riddled with sweatshop abuse, including the human trafficking of tens of thousands of foreign guest workers—mostly from China and Vietnam—to Japan, where they are stripped of their passports and forced to work grueling hours seven days a week, often earning less than half the legal minimum wage. Sixteen-hour shifts, from 8:00 a.m. to 12:00 midnight are common.
Most of the article is referring to labour conditions in Asia.