http://www.economist.com/node/17722932
My ex was a vegan. She always complained about the mistreatment of animals used for food but never thought twice about how the people were treated who picked all the vegetables she ate.
It's basically slave labor in many cases. Low pay, terrible working conditions, long hours. Imagine crawling through the dirt on your knees for 10 hours a day in the California sun, filling buckets of vegetables for $0.80 a bucket, and if you screw up your boss reports you to immigration?
I have family members who were migrant workers just a single generation ago so it hits a little closer to home than some people. But those vegetables don't make it to the store without any suffering, just like pork chops don't.