I'm looking for a way to track who is accessing my Amazon Simple Storage Service (Amazon S3) buckets and objects. How can I do that?
Amazon S3 offers bucket logging, which allows you to see information about requests to your buckets and objects. For an explanation of what's offered in these logs, see Server Access Log Format. For instructions on enabling logging for a particular bucket, see Enabling Logging Using the Console.
You can also use AWS CloudTrail to track API calls to your Amazon S3 resources. For more information, see Logging Amazon S3 API Calls by Using AWS CloudTrail.