To those who say you cannot be banned for watching Netflix, let me just point out that at full bandwidth Netflix consumes ~2 gigabytes per hour, or roughly ~500 gigabytes per month of bandwidth if you have it on 8 hours a day. In other words if you come home and turn it on, and leave it on in the background while you do other things, the way many people treat their television.
I would call that "normal behavior". Consider Netflix as a replacement for cable TV.
Now maybe on mobi the quality would drop to the lowest quality, in which case you would consume only around 75 gigabytes per month.
At what point do they ban you? Watching Netflix does not appear to be against the terms of service, but I am guessing that somewhere between 75G and 500G you would be labelled an "abuser".