1. A method for identifying content items that violates a content policy of a digital content system, the method comprising: receiving a content item comprising at least one digital image; extracting image signals from the digital image of the content item; analyzing the extracted image signals; determining whether the content item is suspicious of containing unsafe or illegal content based on the analysis of the extracted image signals; responsive to a determination that the content item is suspicious of containing unsafe content, verifying the content item with a verification service; and taking an action on the content item based on the verification of the content item.