Posted by Per Bjorke, Senior Product Manager, Ad Traffic QualityAs part of our ongoing efforts — along with help from newly developed technologies — today we’re announcing nearly 600 apps have been removed from the Google Play Store and banned from our ad monetization platforms, Google AdMob and Google Ad Manager, for violating our disruptive ads policy and disallowed interstitial policy. Mobile ad fraud is an industry-wide challenge that can appear in many different forms with a variety of methods, and it has the potential to harm users, advertisers and publishers. At Google, we have dedicated teams focused on detecting and stopping malicious developers that attempt to defraud the mobile ecosystem. As part of these efforts we take action against those who create seemingly innocuous apps, but which actually violate our ads policies. We define disruptive ads as ads that are displayed to users in unexpected ways, including impairing or interfering with the usability of device functions. While they can occur in-app, one form of disruptive ads we’ve seen on the rise is something we call out-of-context ads, which is when malicious developers serve ads on a mobile device when the user is not actually active in their app. This is an invasive maneuver that results in poor user experiences that often disrupt key device functions and this approach can lead to unintentional ad clicks that waste advertiser spend. For example, imagine being unexpectedly served a full-screen ad when you attempt to make a phone call, unlock your phone, or while using your favorite map app’s turn-by-turn navigation. Malicious developers continue to become more savvy in deploying and masking disruptive ads, but we’ve developed new technologies of our own to protect against this behavior. We recently developed an innovative machine-learning based approach to detect when apps show out-of-context ads, which led to the enforcement we’re announcing today. As we move forward, we will continue to invest in new technologies to detect and prevent emerging threats that can generate invalid traffic, including disruptive ads, and to find more ways to adapt and evolve our platform and ecosystem policies to ensure that users and advertisers are protected from bad behavior.