I've heard of other recent cases of slavery, but unfortunately this was the only one I remembered enough details about to find a reference to. I'm guessing that for every case that's discovered and prosecuted, there are many others that are not (seems to be true of crimes in general).

And I certainly have no intention of crapping on America, which has provided me with many opportunities. But I think we should be aware that horrors like slavery can happen here too, not just in far-off countries.