Capital One's breach affecting 100 million Americans and 6 million Canadians was inevitable due to inaction after the Equifax breach, with the article arguing that companies did not take sufficient action to protect consumer data. The breach was caused by a hacker who exploited a vulnerability in a web application firewall. The article suggests that lawmakers and companies are to blame for not taking adequate measures to prevent such breaches. The breach has sparked a debate about data security and the need for stricter regulations.