Along with confusion about ownership of comments, published using Google+ Comments, we see similar confusion about visibility of comments, in Blogger Help Forum: Something Is Broken.
Comments on a Blogger blog are treated the same as Google+ posts, with a Blogger blog using Google+ Comments.
You may see a post shared publicly - or shared with you.
If somebody publishes a Google+ post, and shares the post to a circle that includes you, or shares a post publicly, you may see the post - if you are viewing a stream which includes them. Note that if you Block someone, their posts will never show up in your streams.
If somebody publishes a Google+ post, and shares the post to circle(s) that do not include you - even if the post references your blog - you won't see that post. If somebody publishes a Google+ comment against your blog, and shares the post to circle(s) that do not include you - even if the post references your blog - you won't see that comment.
If you share a post in your blog, you have a comment against that post.
If you share the URL of a post in your blog, in a Google+ post, that post becomes a Google+ comment against your blog post. With a Google+ post, you can choose to share to Public, or to any (or all) of your circles.
If you share the URL of a post in your blog to Public, everybody who is viewing a stream, which includes you, may see your Google+ post. If you share the URL to specific circles, everybody in those circles, and who is viewing a stream which includes you, may see your Google+ post.
If you publish a comment, and choose to share it, you have a stream post.
If you publish a Google+ comment to a post in your blog, and choose "Also share on Google+", that comment will become a Google+ post.
If you share a comment to Public, everybody who is viewing a Google+ stream, which includes you, may see your Google+ post. If you share a comment to specific circles, everybody in those circles, who is viewing a Google+ stream which includes you, may see your Google+ post.
When you view comments in your blog, you may view only Followers.
If you are viewing a post in your blog, you can select the "Circles" icon, and view all comments made by people in your circles, against that post, that you may see - or you can select the "World" icon, and view all comments made by everybody, against that post, that you may see. Anybody else, viewing a post in your blog, can do the same.
If you're publishing a comment against a post in your blog, you can choose to "Also share on Google+". Anybody else, viewing your blog, and publishing a comment, has the same choice.
Google+ shows all posts about your blog, on your blog.
The purpose of Google+ Comments, in Blogger, is to include Google+ posts, about your blog, on your blog.
If you do decide to use Google+ Comments on your blog, be aware of the known problems with Google+ Comments.
You can revert back to Blogger comments - but you won't see Google+ posts.
You can revert the blog back to Blogger Comments - but if you do this, no comments made using Google+ Comments will be visible on the blog, to anybody, from the blog.
We should also mention the issue of Blogger vs Google+ comments - and that you can choose one or the other, at any time. With the blog using Blogger Comments, it will not display any comments made under Google+ - and with the blog showing Google+ Comments, it will not display any comments made under Blogger. If you change back and forth, expect to lose comments.
Also, Google+ comments are based on the URL, not the blog. If you change the URL - as either a BlogSpot to BlogSpot change. or a custom domain publishing - you should also expect to lose comments. The comments will be out there - and with a properly setup custom domain, will direct to the blog - but the comments won't be visible against the blog posts.
I shared the URL of my post in Google+ - and now I see my Google+ post, displayed as a comment, on my blog!and
My comments are showing up in other people's profiles, in Google+!!and
I'm getting notifications, in Google+ - but the comments don't display, on the blog!!Not all blog owners understand the relationship between Google+ comments, published to a Blogger blog - and posts, in Google+.
Comments on a Blogger blog are treated the same as Google+ posts, with a Blogger blog using Google+ Comments.
You may see a post shared publicly - or shared with you.
If somebody publishes a Google+ post, and shares the post to a circle that includes you, or shares a post publicly, you may see the post - if you are viewing a stream which includes them. Note that if you Block someone, their posts will never show up in your streams.
If somebody publishes a Google+ post, and shares the post to circle(s) that do not include you - even if the post references your blog - you won't see that post. If somebody publishes a Google+ comment against your blog, and shares the post to circle(s) that do not include you - even if the post references your blog - you won't see that comment.
If you share a post in your blog, you have a comment against that post.
If you share the URL of a post in your blog, in a Google+ post, that post becomes a Google+ comment against your blog post. With a Google+ post, you can choose to share to Public, or to any (or all) of your circles.
If you share the URL of a post in your blog to Public, everybody who is viewing a stream, which includes you, may see your Google+ post. If you share the URL to specific circles, everybody in those circles, and who is viewing a stream which includes you, may see your Google+ post.
If you publish a comment, and choose to share it, you have a stream post.
If you publish a Google+ comment to a post in your blog, and choose "Also share on Google+", that comment will become a Google+ post.
If you share a comment to Public, everybody who is viewing a Google+ stream, which includes you, may see your Google+ post. If you share a comment to specific circles, everybody in those circles, who is viewing a Google+ stream which includes you, may see your Google+ post.
When you view comments in your blog, you may view only Followers.
If you are viewing a post in your blog, you can select the "Circles" icon, and view all comments made by people in your circles, against that post, that you may see - or you can select the "World" icon, and view all comments made by everybody, against that post, that you may see. Anybody else, viewing a post in your blog, can do the same.
If you're publishing a comment against a post in your blog, you can choose to "Also share on Google+". Anybody else, viewing your blog, and publishing a comment, has the same choice.
Google+ shows all posts about your blog, on your blog.
The purpose of Google+ Comments, in Blogger, is to include Google+ posts, about your blog, on your blog.
For example, if there's a public Google+ discussion about one of your blog entries, those comments and replies will also appear on your Blogger blog.If you do not want to include Google+ comments, about your blog, on your blog, you don't need to enable Google+ Comments.
If you do decide to use Google+ Comments on your blog, be aware of the known problems with Google+ Comments.
You can revert back to Blogger comments - but you won't see Google+ posts.
You can revert the blog back to Blogger Comments - but if you do this, no comments made using Google+ Comments will be visible on the blog, to anybody, from the blog.
We should also mention the issue of Blogger vs Google+ comments - and that you can choose one or the other, at any time. With the blog using Blogger Comments, it will not display any comments made under Google+ - and with the blog showing Google+ Comments, it will not display any comments made under Blogger. If you change back and forth, expect to lose comments.
Also, Google+ comments are based on the URL, not the blog. If you change the URL - as either a BlogSpot to BlogSpot change. or a custom domain publishing - you should also expect to lose comments. The comments will be out there - and with a properly setup custom domain, will direct to the blog - but the comments won't be visible against the blog posts.
Comments
Does your blog use Google+ hosted comments - or Disqus?
Disqus hosted comments will not provide benefits of Google+ association.
http://blogging.nitecruzr.net/2013/04/consider-carefully-decision-to-use.html