While it's true that McDonald's McRibs are made partially out of a substance used to make soles of shoes, there is still a percentage of the limited-edition sandwich that comes from a pig, and that percentage is subject to some horrific mistreatment from the humans that raise it, according to a new lawsuit.

The Humane Society of the US has filed a graphic complaint [pdf] against Smithfield Foods, the pork farm that supplies McDonald's with the odds and ends used in the McRib. The complaint alleges that Smithfield misleads people about their welfare practices—while the farm claims their animals are "raised under ideal conditions in an environment where every need is met," the Humane Society says otherwise.

The complaint states that the pigs live under "hellish conditions," including being crammed into tiny, dirty gestation crates and denied medical treatment for the open sores and ulcers that developed as a result. The Society released a video going "Undercover at Smithfield Foods" in 2010 that they are using to back their claims. Does any of this really come as a surprise? it's not exactly shocking that the country's largest fast-food chain sources their chemical-filled meat from an industrial-scale meat supplier who might possibly value profit above the welfare of their animals.

Smithfield, whom McDonald's granted a "supplier sustainability" award in 2008, denied the allegations in a statement to The Atlantic: "We are proud of our unparalleled track record as a sustainable food producer and stand confidently behind our company's public statements concerning animal care and environmental stewardship," the company said. Any objective assessment of our practices would conclude that Smithfield and our employees are behaving in a socially responsible manner." But if you're not buying what Smithfield's selling, perhaps it's time to consider the socially responsible sandwich.