Yahoo! Japan said they have removed 5900 ads in five months since they came out with new guidelines for ads in the late October 2018.
The new guidelines are structured around 3 pillars:

• Visualization of appropriate advertising effects
• Secured brand value and media credibility (elimination of fraud)
• Provide a stress-free advertising experience

In order to achieve these 3 values, they strengthened the measures in six areas:

• Viewability
• Ad-Fraud
• Brand safety (appropriate delivery)
• Privacy considerations
• Best optimized ad format
• Ad cluttering

It’s nice to see how they work to improve the ad quality and experiences for the customers.