Or people paid to post scripted material, human bots - which I believe there has been evidence leaked at some point that this happens - can't remember where or when or other details unfortunately.
I suspect this is already happening. There was a guide/tutorial posted a while ago on how to hijack a forum/thread and redirect the flow of conversation. I can't find the link but it was very detailed and wouldn't surprise me if someone was profiting from selling such a service as pr/thought/damage control.
It's a major battleground already. The Russians are either far ahead or very unsubtle in this - it's particularly obvious with any story about Russia.