Most of them have the burned feet as they do not have shoes but have to walk on the heated bricks.
They were beaten if work not fast enough, at least one dead. This is not an isolated case, there are many cases, even reported by official newspapers. Many of the factories operate publicly for years.

The most shocking is some factories buy kidnapped children, some are only eight years old. In Boxun's previous report, those parents have found the location of their children for more than a year, but local authority does not rescue them. Recently, they turn their hope to international media.

A few slave worker cases in Chinese:
One official report
Collection of cases

After people read these cases, one question is natural: where is the police? The answer is clear. When police focuses on punishing good person such as Sun Lin (Jie Mu) illegally, they are more likely affiliated with bad guys. There are too many cases that obvious murder incidents were "ignored" by police, while many received death panelty falsely (according to officially released data).