If you're like most people you are currently in a post-Halloween candy and chocolate coma. Karlee Sapoznik wrote a great blog post, "When People Eat Chocolate, They are Eating My Flesh: Slavery and the Dark Side of Chocolate," for Activehistory.ca in 2010, that deals with the dark side of chocolate production.
Some chocolate producers, such as Cadbury have made recent efforts to gain fair trade certification for some of their products, however at this point none of the major chocolate producers are using elusively fair trade coco sources. Additionally, as Karlee's article points out there is some question as to if fair trade chocolate is actually any better than non fair trade items. Regardless, Karlee's article is definitely worth a read given the abundance of Halloween chocolate around at the moment.