Here's a table from a recent report filed with Congress by Social Security's Office of Inspector General (OIG). Notice the huge disparity between the number of allegations received and the number of actual investigations much less criminal convictions. No, I don't think that disparity is because OIG fails to aggressively pursue cases of fraud. I think it's because there's little substance to most allegations of fraud. Republicans can spin it all they want but given Social Security's size, the amount of verifiable fraud at the agency is tiny.