Alliance Data

Alliance Data suffered a massive data breach at the company's Epsilon subsidiary that allowed the names and email addresses of millions of customers at many of the nation's most prominent companies to fall into the hands of hackers.

However, the company actively investigated the incident and assured its clients that the systems are secured now.

Source: https://www.cnbc.com/id/42460188

"id": "ALL23926123",
"linkid": "alliance-data",
"type": "Data Leak",
"date": "04/2011",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"