If your site has a Google+ sharing feature that uses this URL: https://plusone.google.com/_/+1/confirm?url= then you're doing it wrong. You're using unsupported and undocumented functionality. Don't.
That's our official sharelink endpoint. It is supported, monitored and maintained. The URL you're using right now is an internal part of our +1 button's Javascript API so it's subject to change because we don't expect anyone else to be depending on it.
The documentation for the sharelink endpoint is here: https://developers.google.com/+/plugins/share/#sharelink-endpoint It even offers a set of standard graphics that you should be using for consistency with the rest of the web.
In short: don't be like the guy in the photo below.
You should be using a sharing URL that looks like this: https://plus.google.com/share?url=
That's our official sharelink endpoint. It is supported, monitored and maintained. The URL you're using right now is an internal part of our +1 button's Javascript API so it's subject to change because we don't expect anyone else to be depending on it.
The documentation for the sharelink endpoint is here: https://developers.google.com/+/plugins/share/#sharelink-endpoint It even offers a set of standard graphics that you should be using for consistency with the rest of the web.
In short: don't be like the guy in the photo below.