Estonia was nearly shut down last week due to cyber-attacks. Most government computers crashed, banks almost lost track of personal accounts, airports came close to massive air-traffic disaster. Rogue Russian hackers are probably to blame (Estonia unceremoniously removed a Red Army statue,triggering anger and a computer assault).

This is a lesson for the rest of us- the next major terrorist action directed against the U.S. could be a stealth shut-down of most of the internet, obliterating vital records, etc.