The nature of the data involved helps explain why the LinkedIn breach has gotten so much attention. "LinkedIn's data is of much higher quality than other sites," says Paul Kocher, president and chief scientist at (CRI). "There is just so much information about who people really are and what is important to them."

With high-quality information, attackers can launch much more sophisticated and targeted attacks.

But in other respects, the attack isn't out of the norm. "People are shocked by LinkedIn's poor security practices, but this is widespread," Kocher noted. "Plenty of organizations are far worse off than LinkedIn. It's easy to start fixing security when you're motivated by a breach, but until then, many organizations hope for the best."

Passwords: The Root of All Data Breach Evils

A number of recent high-profile attacks (Aurora, RSA, Stuxnet, LinkedIn and attacks on many defense contractors) have been traced to compromised passwords.