Scott Alexander seems to be libertarian too, or at least he seems to like libertarianism more than any other political ideology.
Scott Alexander as in Anti-Libertarian FAQ Scott Alexander?
He's a liberal. You probably think he's a libertarian because there aren't many liberals anymore -- most of the parts of their demographic that ever show up on the internet have gone over to Tumblr totalitarianism instead.
(There's probably a lesson in here about the Dark Arts: don't call up what you can't put down. You summon Jon Stewart, you'll get Julius Streicher within a decade.)
I'm pretty sure that he has recently said
These together imply to me that he favors libertarianism but idk, I could be wrong, I don't think he has ever really come out and said anything about his concrete beliefs on policy proposals. He also seems to not dislike Ayn Rand and talks sometimes about the power of capitalism, iirc.
Cover title: “Power and paranoia in Silicon Valley”; article title: “Come with us if you want to live: Among the apocalyptic libertarians of Silicon Valley” (mirrors: 1, 2, 3), by Sam Frank; Harper’s Magazine, January 2015, pg26-36 (~8500 words). The beginning/ending are focused on Ethereum and Vitalik Buterin, so I'll excerpt the LW/MIRI/CFAR-focused middle:
Pointer thanks to /u/Vulture.