"But today it connects networks of vastly different sorts: computers, yes, but also financial networks, distribution networks, road networks, water networks, power networks, communication networks, social networks."

This is, I hope, incorrect.

Power, water, road, etc. should not be Internet connected and in many cases should not be networked at all.

Homeowners doing cute things with arduino and their lawn sprinklers (and learning good lessons about simplicity and fragility) are one thing. It's quite another to bear the responsibility for critical infrastructure.

I hope the adults in the room have the wisdom and experience to eschew these kind of "improvements".