With this plugin I have let images to be indexed using the sitemap also for pings for media. The Google Index is now full of urls like domain.com/?attachment_id=1876 that I have evaluated to be removed from there.
To prevent further indexing I have thought to put these urls images as noindex. With this plugin I can do it from advanced settings of every images involved. It will be a long work...but I ask to you if these noindexing is only for urls as domain.com/?attachment_id=1876 or it takes also to every images (alt text, caption and so on). Images indexing in Google Images is also useful for Seo...
Thanks to all