Google stopped showing ads on more than 25,000 mobile apps because of policy violations.
The company said it rejected more than 1.4m applications from website and app developers who wanted to run Google ads but not follow policies.
Over 17m ads that misled or tricked people into clicking on them, such as system warnings, were rejected.
More than 10,000 sites and 18,000 accounts were suspended for trying to sell counterfeit goods.
More than 12.5m ads were blocked for breaking Google’s rules on promoting healthcare and medical products.
More than 30,000 sites were banned for making misleading weight-loss claims.
Nearly 7,000 sites were blocked for phishing for web users’ personal information.
More than 10,000 sites offering unwanted software were disabled.
Google vowed that it would continue to battle bad ads, with refined restrictions on suspect weight loss products and new protections against malware and bots.