The Collection #4 data breach is part of a larger series of data dumps, including Collections #1 through #5, which compiled email addresses and passwords from thousands of sources, from previously known data breaches and some new alleged breaches. Collection #1 alone contained about 2.7 billion records, including 1.2 billion unique email and password combinations, 773 million unique email addresses, and 21 million unique plaintext passwords. Additional collections, named Collections #2 through #5, along with "AP MYR&ZABUGOR #2" and "ANTIPUBLIC #1," were also discovered, significantly adding to the scope of compromised data.