为什么这个桶政策是公开的

{
    "Version": "2008-10-17",
    "Statement": [
        {
            "Sid": "AddJPGImageFilter",
            "Effect": "Allow",
            "Principal": {
                "AWS": "IAM user ARN"
            },
            "Action": "s3:PutObject",
            "Resource": "bucket_name/*.jpg"
        },
        {
            "Sid": "AddJPEGImageFilter",
            "Effect": "Allow",
            "Principal": {
                "AWS": ""IAM user ARN""
            },
            "Action": "s3:PutObject",
            "Resource": "bucket_name/*.jpeg"
        },
        {
            "Sid": "AddPNGImageFilter",
            "Effect": "Allow",
            "Principal": {
                "AWS": ""IAM user ARN""
            },
            "Action": "s3:PutObject",
            "Resource": "bucket_name/*.png"
        }
    ]
}

现在据我所知,上述策略意味着可以访问资源(使用 S3:PutObject 允许的操作)仅限于中提到的IAM用户ARN Principal 为了让它公开 * .

Public ?