I spent a good part of this year investigating Google's ad business. Today we published a story about trying to crack open its black box ad network.
Unlike its competitors, Google conceals nearly all publishers it works with and where billions of ad dollars flow. We found that Google's vast ad network contains manga piracy, porn, fraud and disinformation.
Give it a read: https://www.propublica.org/article/google-display-ads-piracy-porn-fraud