It's not about making information disappear, it's about recognizing that humans are very susceptible to mass manipulation (see cults, mass hysteria), and it is becoming an increasingly powerful strategy and weapon in our age of rapidly growing new communications technologies. How to combat this is debatable for sure - I don't think this Youtube stuff is the most effective solution - but I don't think we can just apply old principles to new problems without first acknowledging the real challenges it's meant to address.