If you are viewing the reports for your Google Analytics, Google often displays ( not provided ) as the top keyword for your domain:
Google started making searches secure for users that are logged into their Google accounts (that service that you use for your Google Calendar, Gmail, and Google+ ! ) to protect their privacy. For example, when you’re doing a search, you may see that the URL starts out as https://www.google.com/search? which means that the connection is encrypted. This is the same type of thing you’d see ( the https:// ) when you’re shopping online, and having to enter your credit card details directly into the website.
You’ll know that your visitors have come from organic Google searches, just not what exactly they have typed in to find your site in order to protect their privacy.
So, don’t be alarmed if this comes up as a result in your analytics!