A tip from hackwordpress.com to stop google indexing our images in wordpress. There are two simply ways to do this. The first adding this code to head tag:
<meta name="robots" content="noimageindex">
and the second method is adding code to our robot.txt in root wordpress directory.
User-agent: *
Disallow: /images/
or
User-agent: *
Disallow: /upload/
