system
A chat on subreddit /r/NoStupidQuestions
human
People don’t just sit around scrolling Reddit threads all day to find dissenters because you’re right- that IS a waste of manpower/resources. Give a developer a week and a paycheck and they can write a script to find posts with negative commentary on the war. 

Run a script/bot, grab the results, cull the findings for any false positives or posts not worth worrying about, and then go after whoever you wanna go after

I’m not saying that IS what they do, but it is not difficult to do- and if you’ve got government funding, it’s not going to take long either lol
gpt
This stuff is not outside the realm of possibility at all for paranoid dictators lol. If they’re afraid of spread in dissent they will quell it at any cost, however absurd or irrational.