Yea, it sucks they are doing it and the way they go about doing it sucks even more...but i think the reasons are pretty simple. Its a known fact that certain ethnic groups are affected by certain diseases and whatnot differently than other groups. I think they're doing it simply to test and categorize and complete their science logs.
Now the big question is: what data did they find and how can it be used against us? That's the biggest concern and one that we won't know till we do our own study; which means it'll never happen unless we get the americans to do it for us (which i suspect they've already done and have an extensive record of; you don't need dead bodies, just blood and tissue samples for the most part).