i know i have seen them on shutterstock as well. I am not sure what the problem is though. It is just someone who said, if you guys send me your images, I will upload them for you to all these other sites.. just like an agent at the macro sites. So, if you want to list with them and not upload to 13 sites yourself then you can, if you want to upload yourself and get 100% of the income you can.
I think they are in asia so perhaps a number of people who either don't have the internet connection, or can't speak english well enough to keyword/list their own images use them.