Steganography Detection on the Internet Finding Images Augmented the study by analyzing one million images from USENET discussion groups. Access to the Internet Archive allowed us to analyze images before steganography was mentioned by the press. Results from steganalysis: Most images seem to have content hidden with JPHide. Base-Rate Fallacy: High false positive rate has great impact on efficiency. We assume that hidden messages are rare. Decreasing false positive rate increases efficiency.