Apparently prosecutors are more eager to prosecute slavery victims than actual slavers! How I wish I weren't surprised, but if they can stomach sending people to prison for growing pot, it's not such a step to sending people to prison for being forced to grow pot.
Here's an article from 2008. http://www.newstatesman.com/law-and-reform/2008/11/cannabis-...
And another from 2015. http://mobile.reuters.com/article/idUSKBN0LU00P20150226