Fraudulent online advertising is big business. According to this article, people generating fraudulent ad traffic will pocket an estimated 14% of the $43.8 billion ad revenue in 2015. We need better policing, reporting, open information sharing on repeat offenders, sites, networks. However, until the law catches on and declares this illegal, publishers as well as ad networks, exchanges, SSPs, etc. while ethically against, are all unfortunately incentivised (as they get paid a percentage of online traffic that flows through their systems).
"Bot fraud, digital advertising’s albatross, will suck $6.3 billion from the industry next year, according to a much anticipated report highlighting the threat from the Association of National Advertisers and WhiteOps."
More at: Nearly 25% of Video Ad Views Are Fraudulent, and 6 Other Alarming Stats $6.3 billion menace will shake confidence