The point that's being made is that it's not that hard to disrupt a functioning online community, so you wouldn't even need an army. You could probably do it with a staff of a dozen or less, and honestly looking at how places like reddit and slashdot have transformed over the years I really wouldn't be surprised if there was at least some influence by government agencies(how do those same 5 military propaganda images keep getting to the front page? I'd also be curious to see how those getting to the frontpage compares to recruitment needs for the military. Not saying that it's a conspiracy, but it would be an interesting thing to examine). The tone of those places has changed, and any intelligent, valid criticism of the status quo is consistently ignored and rallied against. I don't know if it's just because people are by and large impulsive and unable to handle criticism, or because of a conspiracy, but the former lends itself to control by the latter.

It would be a bit naive to rule it out completely, but it would be pretty silly to say for certain that it's a conspiracy.