RSA revealed that the majority of breaches are actually caused unintentionally by employees.

This is an interesting article revealing some research by RSA on insider attacks.  Although malicious insider attacks are high, 19%, the majority of insider attacks are believed to be unintentional, 52%.

"The figures are hard to quantify, but the average annual financial loss to insider risk adds up to $800,000 (£480,000) overall per organisation in the US and between $300,000-$550,000 (£180,000-£330,000) in the UK, France and Germany."

"A recent report by the Ponemon Institute found that the average cost of a data breach in 2008 was $202 (£122) per customer record.The information security firm also determined that the expense continued to rise by 38% between 2004 and 2008."

"It advises limiting systems access to a few trusted employees, using a password protection system for logging in, equipping computers with firewalls and virus protection and educating employees."