Digital advertising plays an important role in making the web what it is today. In order for this ads-supported, free web to work, it needs to be a safe and effective place to learn, create and advertise. In 2017, we took down more than 3.2 billion ads that violated our advertising policies. We also introduced technology that allows us to better protect our advertisers by removing Google ads from individual pages on a website that violate our policies. In recent years, scammers have tried to sell diet pills and weight-loss scams by buying ads that look like sensational news headlines.”]
Source: https://www.blog.google/technology/ads/advertising-ecosystem-works-everyone/