Well the 4th technology was easily replaced by majority media control. Which Noam Chomsky describes so well in https://en.wikipedia.org/wiki/Manufacturing_Conse

Well the 4th technology was easily replaced by majority media control. Which Noam Chomsky describes so well in https://en.wikipedia.org/wiki/Manufacturing_Consent https://en.wikipedia.org/wiki/Manufacturing_Consent. There's no need for personalized links, when you can easily control all link targets in mass media via unregulated consolidation.