Have I Been Pwned: Check if your email has been compromised in a data breach
Monster 773 million-record breach list contains plaintext passwords | Ars Technica
"The 773 million email addresses and 21 million passwords easily beat Have I Been Pwned’s previous record breach notification that contained 711 million records. But there are other things that make this latest installment stand out. In all, it contains 1.16 billion email-password combinations. That means that the list covers the same people multiple times, but in many cases with different passwords. Also significant: the list—contained in 12,000 separate files that take up more than 87 gigabytes of disk space—has 2.69 billion rows, many of which contain duplicate entries that Hunt had to clean up."