Gary Illyes from Google posted a PSA (public service announcement) on Google+ warning webmasters not to have noindex directives in their body content because many search engines will see read them and not index the content on that page.
Gary said on Google+:
Please be mindful with noindex directives and remember that most search engines will honour it, even if it's in the BODY element.Check your includes, make sure you're not injecting in the DOM a noindex directive! I found the easiest way to do this is with the Chrome Dev tools: open it up on the page you want to check, hit Ctrl+F (or Cmd+F for those who like fruity flavours), and then type noindex. Nothing found? Great! If you find something like this: <META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
So please don't do this.
Hopefully this blog post will get indexed by Google. ;-)
Forum discussion at Google+.