2012 — LinkedIn: Hacker 'dwdm' uploaded a file containing 6, 8.0M records
Technical writeup
Hacker 'dwdm' uploaded a file containing 6.5 million passwords on a Russian hacker forum. Soon after another 1.5 million passwords were discovered. On analysis, 93% of the passwords could be found in the Top 10,000 password list.
Root cause
Hacked