This wikipedia page[1] is a good start. In particular the last section about dead peasants insurance is the first story I encountered about Walmart's harmful practices.
> Critics, as well as the United States Internal Revenue Service, charge that the company was trying to profit from the deaths of its employees, and take advantage of the tax law which allowed it to deduct the premiums.
> Critics, as well as the United States Internal Revenue Service, charge that the company was trying to profit from the deaths of its employees, and take advantage of the tax law which allowed it to deduct the premiums.
[1] https://en.wikipedia.org/wiki/Criticism_of_Walmart