If you wish for your Exposure site and stories to not be indexed by search engines (like Google and Bing) you can request for them to ignore your content. While we can not guarantee it will be honored, most services do listen to the request.

Once it enabled it can take sometime to kick in. This is due to not know the crawl schedules for each search engine. 

Request Your Stories and Site Not Be Indexed by Search Engines is managed from your Site Preferences.