The concern is over what will happen as strong encryption becomes commonplace with all digital communications and stored data. Right now the use of encryption isn't all that widespread, but that state of affairs is expected to change rapidly.

Everyone is a proponent of strong encryption.

If we take as given that critical infrastructures are vulnerable to a cyber terrorist attack, then the question becomes whether there are actors with the capability and motivation to carry out such an operation.

Generally I'm against regulation.

While the vast majority of hackers may be disinclined towards violence, it would only take a few to turn cyber terrorism into reality.

Systems are complex, so controlling an attack and achieving a desired level of damage may be harder than using physical weapons.

While many hackers have the knowledge, skills, and tools to attack computer systems, they generally lack the motivation to cause violence or severe economic or social harm.