The rockyou.com insight was new to me. I hadn't heard of this breach somehow. I was wondering how they had 32m users and read some more on Wikipedia and they had Facebook apps and some MySpace plugins.
From Wikipedia
> In December 2009, RockYou experienced a data breach resulting in the exposure of over 32 million user accounts. This resulted from storing user data in an unencrypted database (including user passwords in plain text instead of using a cryptographic hash) and not patching a ten-year-old SQL vulnerability. RockYou failed to provide a notification of the breach to users and miscommunicated the extent of the breach