We have a habit of using anything that Google Image throws at. Can't blame the users, they see no details about the terms of use. But every digital content has a license associated with it and Google will now start displaying it to you which image search
To tell Google which images are licensable, add metadata to each licensable image on your site. If you have the same image on multiple pages, add metadata for each image on each page that it appears.

Image License Metadata in Google Images (BETA)
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