This SCP prevents users or roles in any affected account from deleting any S3 bucket or objects.

 
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "s3:DeleteBucket",
                "s3:DeleteObject",
                "s3:DeleteObjectVersion"
            ],
            "Resource": "*",
            "Effect": "Deny"
        }
    ]
}
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