They're very blatantly using astroturfing and shilling to silence people who go against their idea of the way things should be. I doubt HN is going to have an astroturf quotient as high as someplace like reddit, though.
It's similar to people who say things like "I know I'm going to get downvoted, but". Instead of making assumptions about the nature of a discussion in a comment people should wait for the discussion to develop before judging.
If you know someone is astroturfing call it out. If a post isn't appropriate or isn't contributing to the discussion call that out. Just don't assume that people are participating in bad faith, especially before that participation has even occurred.
Specifically, conversations regarding Israel's involvement with Palestine or Russians involvement in Ukraine tend to become very quickly polluted by vast swathes of low-quality comments which effectively shut down discussion.
Maybe the quality of discussion on HN would be better if there were fewer such 'warnings', and not more?
What JTRIG does is far worse, and should really be called the continuation of COINTELPRO. Astroturf-style posting is only one of the tools in their toolbox.
The evidence and movement of the "cyber war department" says otherwise. Within the last 5 years or so there has been an explosion of government requests for bids for persona management and other sock puppetry accounts, and quite a few companies have been making quite a bit of money off it, very quietly of course.
Now, lets not be hasty and call anyone who disagrees with a thing a "shill", but also lets not bury our head in the sand and pretend it's not happening and a very real threat to the normal evolution of discussion on the internet.
Instead of dumping a ton of RFB links I'll just give you a guardian article.
http://www.theguardian.com/technology/2011/mar/17/us-spy-ope...
I am sure there are plenty of government and military bureaucrats who aren't bothered by futility of their efforts, but the leaks we've seen so far suggest that the NSA, at least, are competent at achieving their goals.
I have seen minds changed quite frequently on the internet, and I think the cynical attitude towards internet discussions isn't helpful. It largely depends on the forum and it's quality though. For example, HN is a great place for people to find factual correction from peers, and I see it daily here. On reddit, subs like /r/askhistorians or /r/engineering are also places where I see factual correction taken as it should be, that is to say as constructive criticism.
Now, regarding the "effectiveness" you refer to, I think you need to broaden your idea of the definition. If you are thinking that sock puppets are there to change minds, you are severely mistaken. I would venture to say that most sock puppet tactics are based on some variance of distraction or pushing of topic or conversational tone. It's a complex topic with a myriad of techniques that can be applied by corporate PR just as easily as a government. If you want to know more, try the following:
This is one of the details which should probably be considered when trying to spot the presence of shills or agents here, that HN is engineered with a bias to begin with.
Although, according to that clearly authoritative pastebin, questioning a conspiracy is evidence of a conspiracy.
And if all government propaganda agents did was correct peoples' factual errors, I would welcome them wholeheartedly.