I don't believe I am a Google+ user and I am trying to minimize my use of Google products. I believe that I took a specific action to ensure I am not a Google+ user at some point in the past. I do use gmail and I am under the impression that if I use gmail, I have at some point in time been classified, on Google's initiative and perhaps without my knowledge of it (because I don't want to read boring user agreements), as having a Google Account. I believe that Google Account is sufficient to allow logging into stackexchange websites.

However, the logo on the stackexchange login appears to be a Google+ logo.

Is the logo the wrong logo and should it be replaced with some sort of Google Account branding?