In what appears to be the largest digital advertising scam in history, a group of Russian hackers reportedly built a click-fraud machine that stole up to $5 million daily from top advertisers and publishers. But even that is just the tip of the iceberg when it comes to online ad fraud.
Article Link: http://venturebeat.com/2016/12/20/russian-methbot-stole-5-million-daily-with-ad-fraud-scheme/