You're reading a lot into "probably."

I'd expect that someone whose day job is to comment on forums to be better at writing comments than someone who only comments on forums as a hobby. That seems how it is in most professions.

It seems like without explicitly defining our experimental terms, the reverse (there are literally zero sockpuppet comments on the linked page) is equally unfalsifiable. Personally, if I were talking to a friend about what comments we've written on the Internet, and she mentioned writing a comment on that page, I'd take it as a virtual certainty that that particular comment was not written by a sockpuppet, so I don't think my belief is unfalsifiable.

>If you think you see it everywhere, I would submit the government might have far more control over you than you believe.

...no, I see propaganda pretty much everywhere. Less so now that I live outside a major city, but when I did there'd be propaganda all over the place.

You might be seeing propaganda as too narrow a term. Propaganda is just government advertising, sometimes related explicitly to supporting politicians but more often related to rather mundane things. "See something, say something" is propaganda. Ads on the bus or on bus stops about the risks of jaywalking are propaganda. Highways have maybe one propaganda sign every 50 miles, on average (this might be an East Coast thing). "Click it or ticket" was propaganda (and beautiful propaganda at that).

And that's just considering only things explicitly put up by the government. Bumper stickers are propaganda for political parties. You can go to the more government-dominated metro stations in DC and see propaganda advertisements from Boeing, Raytheon, Palantir, etc., aimed at politicians. Activist and advocacy groups produce propaganda full-time.

I suggest checking out the PropagandaPosters subreddit. There's great propaganda from World War II or the Cold War (from all over the world), but also a large amount of modern propaganda.