I wonder why the HN account name field is optional, for getting in the shared circle. Currently, it looks like anyone can add themselves just by having an emai

I wonder why the HN account name field is optional, for getting in the shared circle. Currently, it looks like anyone can add themselves just by having an email and G+ account. Someone already mentioned OAuth, and it'd be great if proper auth against both G+ and HN was required to be added to the circle. On the other hand, it's also not that hard to selectively toss someone out of your copy of the circle, even right from the stream page.