“But despite alarms as far back as 2008, Home Depot was slow to raise its defenses, according to former employees.”
Apparently Home Depot ex-employees had a wealth of information,
“Some members of its [The Home Depot] security team left as managers dismissed their concerns. Others wondered how Home Depot met industry standards for protecting customer data. One went so far as to warn friends to use cash, rather than credit cards, at the company’s stores.”
Ignored warnings from security staff was also noted in the Target incident. Target ex-security staff warned management long in advance but management refused to acknowledge concerns. In both these cases, the companies had advanced knowledge security weaknesses existed, willfully refused to improve, and even ousted outspoken security staffers to the peril of cardholders.