Reducing Photo-Tagging Spam

A photo spam detector detects illegitimate non-natively captured images through extracting image features and feeding the extracted features into a probabilistic model. The probabilistic model categorizes the photo as legitimate or illegitimate. Requests to tag one or more users in a photo are analyzed by a tag analyzer that assesses relationships between the tag requests themselves, social relationships between the tagged users, and the presence or absence of faces within the regions specified by the tag requests. Based on the classification of images or tags as illegitimate, a social networking system applies one or more social media distribution policies to the image or tags to suppress or prohibit distribution.