keyplyr - 9:38 am on Jan 28, 2013 (gmt 0)
If you are on Apache servers, you can add a line to an .htaccess file in the directory where your images are:
Header append X-Robots-Tag: noindex
to prevent your images from being indexed (in the future, anyway). This adds a noindex metatag to your images AND any other files in the directory served by that .htaccess file - so it is not for your site's .htaccess file or all your files will be noindexed.
@Not2easy - theoretically this should work and I even posted this as a solution in the thread for the New Bing Image Search a few weeks ago. I have the X-Robots-Tag: noindex in the headers for all files in my image directories - yet - Google Image Search and Bing Image Search still display my images from these directories.
And I was careful not to prohibit their image bots from access to these image files, either by blocking UA or disallowing them in robots.txt, so that the headers could be read.
I have sent both Bing and Google numerous emails/feedback without any response. I can only conclude they're telling us "screw you we'll do what we want."