1. A method performed by one or more server devices, the method comprising: extracting, by the one or more server devices, a visual feature from an image that is associated with a web site, where the extracted visual feature of the image includes a color; determining, by the one or more server devices, a score for the image, the score representing a likelihood that the image includes inappropriate content, where the score is based on: the extracted visual feature of the image, and one or more other scores, associated with a distribution of the extracted visual feature across one or more other images associated with the web site; associating, by the one or more server devices, the determined score with the image; associating a tag with the image, based on the score; and using, by the one or more server devices, the tag to determine whether to provide the image to a user.