I love Angie's response, about how thorny this all is, and how we have to set our own standards and prioritize the things that are important to us. I sometimes find myself paralyzed when I try to research everything to make the absolute best possible choice. It's impossible!
Case in point: I have two brothers. Brother 1 works in international trade for a large retail company that most of us wouldn't hesitate to slap on our "unethical" list (in fact, it's already been mentioned in this thread). Brother 2 owns a small business with two locations. Recently, Brother 2 posted photos of a sourcing trip he went on for his small business, and Brother 1 was AGHAST. He pointed out that his company would never be able to get away with the conditions Brother 2 was showing in his photos, because the spotlight on them is too bright.
I guess the moral is, as consumers, we have to keep those spotlights shining and continue talking about what we expect from businesses, large and small. It makes a difference. Those big companies are hearing, and many of them are definitely trying to make changes, but they're not 100% there yet, so we need to keep telling them. Probably forever.