“In total, 13,124,962 of these records (or 7 GB of data) have been exposed in the breach, potentially implicating more than 200,000 people in unethical activities.”
The scheme is simple. Buy the product, post five stars, get refunded through PayPal so Amazon never sees the payment. Amazon didn’t catch it. An unsecured Elasticsearch server did. The star ratings you shop by were bought and paid for.