"Facebook’s security team seeks out the hacked information and cross-checks it with credentials used by its members. “We try and monitor those channels proactively,” said Matt Jones, an engineer on Facebook’s site integrity team.How Facebook Tries to Protect Users' Online Credentials - NYTimes.com
If a match is found between hacked credentials and those used for Facebook accounts, Facebook can lock out the affected accounts. Then, the next time the users log in, they are notified that because their information was compromised elsewhere, they must go through additional steps to verify their identity and must change their log-in credentials."
Tuesday, April 03, 2012
How Facebook Tries to Protect Users' Online Credentials - NYTimes.com
Hacked profiles as an open data source