Adobe: In October 2013, 153 million Adobe accounts were breached with each containing an internal ID, username, email, encrypted password and a password hint in plain text. The password cryptography was poorly done and many were quickly resolved back to plain text. The unencrypted hints also disclosed much about the passwords adding further to the risk that hundreds of millions of Adobe customers already faced.

Compromised data: Email addresses, Password hints, Passwords, Usernames

Anti Public Combo List (unverified): In December 2016, a huge list of email address and password pairs appeared in a "combo list" referred to as "Anti Public". The list contained 458 million unique email addresses, many with multiple different passwords hacked from various online systems. The list was broadly circulated and used for "credential stuffing", that is attackers employ it in an attempt to identify other online systems where the account owner had reused their password. For detailed background on this incident, read Password reuse, credential stuffing and another billion records in Have I been pwned.

Compromised data: Email addresses, Passwords

Collection #1 (unverified): In January 2019, a large collection of credential stuffing lists (combinations of email addresses and passwords used to hijack accounts on other services) was discovered being distributed on a popular hacking forum. The data contained almost 2.7 billion records including 773 million unique email addresses alongside passwords those addresses had used on other breached services. Full details on the incident and how to search the breached passwords are provided in the blog post The 773 Million Record "Collection #1" Data Breach.

Compromised data: Email addresses, Passwords

Disqus: In October 2017, the blog commenting service Disqus announced they'd suffered a data breach. The breach dated back to July 2012 but wasn't identified until years later when the data finally surfaced. The breach contained over 17.5 million unique email addresses and usernames. Users who created logins on Disqus had salted SHA1 hashes of passwords whilst users who logged in via social providers only had references to those accounts.

Compromised data: Email addresses, Passwords, Usernames

Forbes: In February 2014, the Forbes website succumbed to an attack that leaked over 1 million user accounts. The attack was attributed to the Syrian Electronic Army, allegedly as retribution for a perceived "Hate of Syria". The attack not only leaked user credentials, but also resulted in the posting of fake news stories to forbes.com.

Compromised data: Email addresses, Passwords, User website URLs, Usernames

LinkedIn: In May 2016, LinkedIn had 164 million email addresses and passwords exposed. Originally hacked in 2012, the data remained out of sight until being offered for sale on a dark market site 4 years later. The passwords in the breach were stored as SHA1 hashes without salt, the vast majority of which were quickly cracked in the days following the release of the data.

Compromised data: Email addresses, Passwords

MySpace: In approximately 2008, MySpace suffered a data breach that exposed almost 360 million accounts. In May 2016 the data was offered up for sale on the "Real Deal" dark market website and included email addresses, usernames and SHA1 hashes of the first 10 characters of the password converted to lowercase and stored without a salt. The exact breach date is unknown, but analysis of the data suggests it was 8 years before being made public.

Compromised data: Email addresses, Passwords, Usernames

Trik Spam Botnet (spam list): In June 2018, the command and control server of a malicious botnet known as the "Trik Spam Botnet" was misconfigured such that it exposed the email addresses of more than 43 million people. The researchers who discovered the exposed Russian server believe the list of addresses was used to distribute various malware strains via malspam campaigns (emails designed to deliver malware).

Compromised data: Email addresses

Verifications.io: In February 2019, the email address validation service verifications.io suffered a data breach. Discovered by Bob Diachenko and Vinny Troia, the breach was due to the data being stored in a MongoDB instance left publicly facing without a password and resulted in 763 million unique email addresses being exposed. Many records within the data also included additional personal attributes such as names, phone numbers, IP addresses, dates of birth and genders. No passwords were included in the data. The Verifications.io website went offline during the disclosure process, although an archived copy remains viewable.

Compromised data: Dates of birth, Email addresses, Employers, Genders, Geographic locations, IP addresses, Job titles, Names, Phone numbers, Physical addresses