If you choose to use pluss, an authentication token provided to pluss by Google will be stored in its database. This token can be linked to the publicly available information from your Google+ profile. However, this token will not be shared with other users of the pluss service; it is only used internally by pluss to access the Google+ API.
pluss serves as a proxy for public Google+ posts. As such, it will use the authentication token provided when you initially authorize it to retrieve public posts and profile information from your Google+ account. This information may be cached on the pluss server to provide better feed performance, but will not be used for purposes other than providing this proxy service.
When you use pluss, certain information will be automatically collected and stored in server logs. This information includes your IP address and the pluss URL(s) accessed via that IP address. These logs will only be used for diagnostic and anonymous analysis purposes, and will not be disclosed to other users of the service.
pluss provides access to content you have already made public on Google+. As such, it does not make any effort to conceal or otherwise keep private the content it proxies. Please keep this in mind when choosing what you post publicly.
By using pluss, you give it permission to act as a proxy for the public content on your Google+ account. If at any time you wish pluss to stop proxying your content, simply revoke its access from your Google Account settings.
pluss does not share any information beyond that available in your public Google+ stream.