What do you think our greatest threats are? Phishers, crackers, Nigerian princes? How about hacktivism, a rising force with LulzSec and Anonymous donning Guy Fawkes masks and going to it.
Sophos puts out a great series of technical reports. You can read this one at http://www.sophos.com/en-us/security-news-trends/reports/security-threat-report/html-01.aspx