Source
I'm surprised Uber isn't already doing this.
4.6 is pretty high of a bar, though, which probably means that most riders are probably going to be rated 5/5 unless there's a serious issue. Thoughts?
EDIT: 4.6 is for driver ratings. The rating which riders will be kicked off isn't mentioned but supposedly "only a few" will be affected. I guess it'll depend on how inflated the current rider ratings are.