If you have contacts blocked in any Google products, such as Google Hangouts, these contacts will now show up as blocked in your Chat list as well. Google+ synchronizes all of your blocked contacts across all Google properties.However, if you block the person in Google+, in addition to being removed from your circles and extended circles, they will also be unable to chat with you in any Google Chat property (i.e. So, although they won't be able to chat with you, they'll still be in your Circles and be able to see your content. Blocking someone from within the Chat list or a Chat window does not also block the person in Google+.You cannot block someone from within the Chat window in Google+.