WHSmith

WHSmith experienced a data breach incident in September 2015 because of a glitch in its IT system.

Its website randomly started sending out hundreds of private emails to people on its mailing list which resulted in the leakage of data of about 22 customers.

The compromised data included real names, phone numbers, postal addresses, and email addresses of people trying to contact WHSmith.

WHSmith immediately took preventive steps and apologized to the impacted persons.

Source: https://www.wired.co.uk/article/whsmith-data-breach-customer-emails

"id": "WHS233319422",
"linkid": "whsmith",
"type": "Breach",
"date": "09/2015",
"severity": "75",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"