A few tried, even specifically operating under the theory that the failures in Russia would make a post-assassination coup politically possible, in Operation Spark.
I don't think this much affects your point, though; by the time a sufficiently evil person and/or group is in power, there doesn't seem to be any shortage of political and psychological mechanisms they can use to entrench there.
Scott, known on LessWrong as Yvain, recently wrote a post complaining about an inaccurate rape statistic.
Arthur Chu, who is notable for winning money on Jeopardy recently, argued against Scott's stance that we should be honest in arguments in a comment thread on Jeff Kaufman's Facebook profile, which can be read here.
Scott just responded here, with a number of points relevant to the topic of rationalist communities.
I am interested in what LW thinks of this.
Obviously, at some point being polite in our arguments is silly. I'd be interested in people's opinions of how dire the real world consequences have to be before it's worthwhile debating dishonestly.