Sony hack is potentially the worst in history. 100 TB stolen.
gizmodo.com
gizmodo.com
N Korea has proven track record of hacking attack.
http://arstechnica.com/security/2013/07/hard-drive-wiping-ma...
A few years ago, N korean hackers go into a bank (IBM in S Korea helped maintain/secure it) and wiped their primary database AND standby backup database. By the time they realized what was happening, even the backup site off useless.