Network is the Message

What does Castells mean when he suggests that the "Network is the Message" in the prologue to his text?

Castells defines a network as a set of interconnected nodes. He discusses how Internet was designed as free communication and has become the fastest growing form of media.  Castells believes that the Internet has great advantages over other forms of media because it is more flexible and has better adaptability.  Castells suggest that the "network" is our future of communication, and especially media, as long as we are careful and resourceful of how we use it.

(Information from Castells "Internet Galaxy")