1. Amazon ec2 pricing,
http://aws.amazon.com/ec2/pricing/
(retrieved October 22, 2012)
2. Cert incident note in-98.03: Password cracking activity (July 1998),
http://www.cert.org/incident_notes/IN-98.03.html
(retrieved August 16, 2011)
3. Geek to live: Choose (and remember) great passwords (July 2006),
http://lifehacker.com/184773/geek-to-live--choose-and-remember-great-passwords
(retrieved September 27, 2012)
4. Rockyou hack: From bad to worse (December 2009),
http://techcrunch.com/2009/12/14/rockyou-hack-security-myspace-facebook-passwords/
(retrieved September 27, 2012)
5. Oh man, what a day! an update on our security breach (April 2010),
http://blogs.atlassian.com/news/2010/04/oh_man_what_a_day_an_update_on_our_security_breach.html
(retrieved August 18, 2011)