You are wrong about the CSS. What was happening was: the brigades of pro-fork users would downvote anyone who disagreed with them.
Reddit hides posts that score -5 or lower. So, the moderators changed the CSS to show all posts (even < -5 posts) as an anti-censorship tool. The reddit.com administrators are aware of this.
As for sorting by Controversial - same concept. The pro-fork brigades would force popular posts to the bottom, now the moderators use the built-in Reddit sort tool to make those appear higher up, in threads where vote manipulation happens.
Because reddit lets anyone create an account in about 3 seconds, it is easy to game and control what gets seen and what does not. Hacker news does the right thing by not giving everyone a downvote button on the first day.
No other subreddit that I am aware of engages in this form of comment manipulation. I am not even a Bitcoin user but this sort of behaviour was extremely unusual.