Readyshare for NAS?

Thanks a ton. Do you find that the WD to go works best? Also, I know this may be a silly question, but if I give some of my family, like my mom, uncle, etc my log in info, and they watch movies I have on the NAS, will that be pulling from my bandwith? I mean, if there are 4 people (from outside my home network) that are trying to copy a movie to their desk or watch a movie, wll that make it drag for me at home?

Thanks again!