Professional Cyber companies all agree the greatest threat regarding cyber security is an attack on a countries critical infrastructure.  History shows that an attack on a country includes taking out critical infrastructure such as gas, hydro, water etc., you quickly disable the enemy.  This infrastructure is now vulnerable due to access via the internet.  While highly secured it is not invincible to an attack, our military is planning a strategic defense and offence.

http://www.msn.com/en-ca/news/canada/canada-nato-attempt-to-define-boundaries-of-response-to-cyberattacks/ar-BByzZj5?li=AA521o&ocid=spartandhp