Have you started seeing a new item in your Google Analytics keyword report that says (not provided)? Instead of showing you the keyword that users typed into Google to find your site, you see an item that says (not provided).
If you search in Google while signed into a Google account, those searches are encrypted. That is why you see “not provided” instead of the keyword. As more and more people search while signed into their Google accounts, that will make it harder for you to determine how search traffic reached your site and will hurt your SEO efforts.