The internet as a medium for social change fails right where it succeeds. Grassroot movements are quickly swamped by the sheer quantity of banality. As a resource to communicate it is unparalleled, but only as far as it can reach out to those who wish to be communicated to. As with TV, you can just switch over, and people frequently do. (although the similarities end here, as TV content is almost purely drivel, and the gatekeepers are tirelessly working to wrap up the rest).
As a culture we are easily the most distracted in history, and we are not equipped with the training to ignore those distractions and push through the important words. When faced with the kind of information available, most people resort to the usual apathetic mush. Content is measured in eye real-estate and viewing seconds, not in quality.
With arguably the most powerful communication tool ever conceived, available to us, we do nothing. Socially, faced with a huge crisis, we do nothing. I see no protests. I see no demonstrations. No galvanized populaces. No directed anger. The only thing I hear is the faint hiss as our impetuous is siphoned off into one or more modes of distraction.
The internet should be more than it is, a delivery vehicle for information, not an information dump. Would you rather read paragraph after paragraph of text, or watch someone face-plant on YouTube?
When one tries to buy soap in a supermarket, we are given hundreds of different choices. Much like viewing material on the web, when confronted with this, we invariably choose the brightest and most colorful packaging, regardless of the contents within.