End of "AWS S3 security" excuse (when there is a data breach) - We have a new feature in AWS - AWS Identity & Access Management Access Analyzer

- It Monitors S3 bucket access policies and provides alerts if you have a cloud-storage bucket that is configured to allow access to anyone on the internet or that is shared with other AWS accounts. If the Access Analyzer tool discovers that a bucket is misconfigured you can respond to the alert by making a single click to "Block All Public Access,"

https://businessinsights.bitdefender.com/amazon-battles-leaky-s3-buckets-with-a-new-security-tool