Last year, Google took down more than 700,000 apps that violated the Google Play policies, 70% more than the apps taken down in 2016.

The company removed more bad apps, but also was able to identify and action against them earlier. In fact, 99% of apps with abusive contents were identified and rejected before anyone could install them, said Andrew Ahn, Product Manager, Google Play. This was possible through improvements in Google's ability to detect abuse - such as impersonation, inappropriate content, or malware - through new machine learning models and techniques.

Google has also developed new detection models and techniques that can identify repeat offenders and abusive developer networks at scale. This resulted in taking down of 100,000 bad developers in 2017, and made it more difficult for bad actors to create new accounts and attempt to publish yet another set of bad apps, Ahn added.

According to Google, examples of bad apps include those which
are attempting to deceive users by impersonating famous apps; apps that contain or promote inappropriate content, such as pornography, extreme violence, hate, and illegal activities; and apps that conduct SMS fraud, act as trojans, or phishing user's information.