I have doubts the effects would be as envisioned. There might be negative social/biological traits (ex: fear is stronger than happiness; low threshold for believing things) that amplified by the exponential effect of such a network can have disastrous results. We had tyrants, cult leaders and other nuts that made enough damage without such a tool.
Maybe the network should also limit interaction and exposure. It's fine if you get more interaction than you could do in real life, but I find worrying to have one person followed by tens of millions ... (and even if it was the case before with newspapers, I don't think it was ideal either)