Top 10 Worst Data Breaches in History

A background check company leaked 2.9 billion records including Social Security numbers, names, and addresses of nearly every American, Canadian, and British citizen.

A preventable Apache Struts vulnerability exposed 147 million Americans' Social Security numbers, birth dates, and credit histories from one of the three major credit bureaus.

Hackers lurked in Starwood's reservation system for four years before Marriott discovered 500 million guest records including passport numbers had been stolen.

Personal data of 87 million Facebook users was harvested without consent and used for political advertising, sparking a global reckoning about social media and democracy.

Data from 700 million LinkedIn users — 93% of the platform — was scraped and posted for sale, including email addresses, phone numbers, and geolocation records.

The Clop ransomware gang exploited a zero-day in MOVEit file transfer software, compromising over 2,600 organizations and 77 million individuals across government and enterprise.

Russian hackers compromised SolarWinds' software update mechanism, infiltrating 18,000 organizations including the US Treasury, Department of Homeland Security, and Fortune 500 companies.

Attackers stole 40 million credit card numbers and 70 million customer records through a compromised HVAC vendor, becoming the breach that made boardrooms take cybersecurity seriously.

Sony's gaming network went dark for 23 days after hackers stole 77 million accounts including credit card data, costing the company an estimated $171 million.

A background check company leaked 2.9 billion records including Social Security numbers, names, and addresses of nearly every American, Canadian, and British citizen.

A preventable Apache Struts vulnerability exposed 147 million Americans' Social Security numbers, birth dates, and credit histories from one of the three major credit bureaus.

Hackers lurked in Starwood's reservation system for four years before Marriott discovered 500 million guest records including passport numbers had been stolen.

Personal data of 87 million Facebook users was harvested without consent and used for political advertising, sparking a global reckoning about social media and democracy.

Data from 700 million LinkedIn users — 93% of the platform — was scraped and posted for sale, including email addresses, phone numbers, and geolocation records.

The Clop ransomware gang exploited a zero-day in MOVEit file transfer software, compromising over 2,600 organizations and 77 million individuals across government and enterprise.

Russian hackers compromised SolarWinds' software update mechanism, infiltrating 18,000 organizations including the US Treasury, Department of Homeland Security, and Fortune 500 companies.

Attackers stole 40 million credit card numbers and 70 million customer records through a compromised HVAC vendor, becoming the breach that made boardrooms take cybersecurity seriously.

Sony's gaming network went dark for 23 days after hackers stole 77 million accounts including credit card data, costing the company an estimated $171 million.