Have you received warning Email or/and message from Google Plus stating the violation of Google’s User Content and Conduct Policy ? If yes, then its time for you to change some of your G+ using habits. You have done some mistakes which made Google send you warning message. The mail sent by Google may read as given below or a little different depending on policy you violated:
We’ve determined that your posts have repeatedly or egregiously violated our User Content and Conduct Policy.
Spamming, including sending unwanted promotional or commercial content, or engaging in unwanted or mass solicitation, is not permitted.
Your access to Google+ will be limited for two weeks. If you continue to violate our policies, your access to Google+ and Google’s other social services, such as Hangouts, may be suspended permanently. Learn more
Please review our policies to avoid violating them in the future. If you believe this decision was made in error, please submit an appeal.Learn more
We understand that these policies may not be for everyone. If you choose to leave, you can make a copy of your Google+ data first. If you like, you can also disable Google+ entirely.
The Google+ team
Google Inc., 1600 Amphitheatre Parkway, Mountain View, CA 94043 USA.
You might have received the warning from Google due to any of the reasons like making hate speech, using abusive language, spamming, sharing links from the commercial websites, sharing same content in many communities, posting pornographic content or violating community guidelines and rules, impersonating someone, indulging in illegal activities etc.
Biggest reason might be you shared same post in several communities or repeatedly shared links from a particular website (commercial one) which resulted in alerting Google+ content filters to mark you as spam. These are all against Google’s policies.
What to do now ?
Do not worry, just don’t post anything on your Google Plus account for next 24 hours.
Avoid the mistakes that people usually make while using G+ to evade any such further warning from Google+ which may result in disabling some or all of your Google Plus features and in extreme cases suspend your G+ and Gmail account.