IF YOU ENABLE GOOGLE+ COMMENTS ON YOUR BLOG
Google’s made it so you can use Google+ to handle your comments on Blogger.
Except, whoops, when you do that ONLY people with Google+ accounts can comment on your blog. So, enabling that feature locks out anyone who doesn’t want to use Google+.
So, don’t do that.
Until, of course, they make it mandatory.
(Very glad I shifted to WordPress.)