Personally I would never ever trust them. I am not even American, yet am paranoid about the Chinese!
Here is a quick link, but I have been hearing about these things for a long time. Do your own research on this and be a little worried.
Like I said, do your own research as that is just a quick link I threw up, there will be better more reputable sources with the same information. Either way, I don't fancy having anything to do with that!