Hundreds of millions of people contribute over 20 million reviews, ratings, and other pieces of content to Google Maps’ over 200 million points of interest daily — it’s how the platform continues to grow so rapidly. But user contributions are intrinsically fraught. That’s why increasingly, Google is using AI and machine learning to spot malicious contributions at submission time, ensuring they don’t reach the over 1 billion users who regularly use Maps.

In a blog post, Google said that it uses automated detection systems, including machine learning models, to scan millions of contributions to detect and remove policy-violating content. In the case of reviews, its systems audit every review before they’re published to Maps, looking for signs of fake or misleading content. And its machine learning models watch for specific words and phrases and examine patterns in the types of content an account has contributed in the past, while taking into account suspicious review patterns

Of course, AI isn’t perfect, which is why Google employs teams of trained operators and analysts who audit reviews, photos, business profiles, and other types of content, both individually and in bulk. In 2019 alone, with the aid of machine learning systems that improved in their ability to block policy-violating content and detect anomalies for manual review, human moderators removed more than 75 million policy-violating reviews and 4 million fake business profiles. They also took down more than 580,000 reviews and 258,000 business profiles that were reported directly to Google, and they reviewed and removed more than 10 million photos and 3 million videos that violated Maps’ policies and disabled more than 475,000 user accounts.

“The vast majority of contributions made to Maps are authentic, with policy-violating content seen less than one percent of the time. And we’ll continue to develop new tools and techniques to fight against bad actors,” said Maps director of product Kevin Reece. “Contributed content is an indispensable part of how we’re making Maps richer and more helpful for everyone.”

The metrics update comes after a Wall Street Journal report concluded that there are millions of fake listings on Maps, which have since been removed by Maps’ moderation team. In response to this and other controversies relating to user-submitted content, including an incident involving a drawing of an Android logo urinating on an Apple logo, Google has at various points shuttered public map editing tools and introduced new Maps moderation features.

This purge highlights an important point to anyone thinking of trying to manipulate their reviews to look better to new customers. If your ordinary business practices are such that you are regularly generating negative reviews, then any attempt at growing your business will in turn just generate negative reviews. That’s why it’s better to address the underlying problem than try and cover it up with fake reviews. Besides, it would sure suck to put a lot of work into securing a bunch of fake reviews only to wake up one morning to see them all wiped out by Google’s AI.