While assurances from the founders make (classically) liberal idealists all warm and fuzzy inside, they aren't worth much until there is a controversy to use this post as a measuring stick on. At that point, we'll have a more clear idea of exactly where they draw the line, which I'd be interested in knowing as a supporter of the company. Regardless, Substack seems to have high quality built in off ramps to the point where deplatforming someone from Substack won't have the same memory holing effect that it does with social media.<p>The best (and worst depending on which side of this future controversy I find myself on) part of Substack is the lack of switching costs. No one is staying on Substack for their barebones content editor, and retaining your own mailing list (and now custom domain!) makes firing up a Ghost newsletter easy. Their other value adds like legal support and revenue advances will most likely never be given to anyone of guilty of sufficient offense to be kicked off the platform, so that point is moot when it comes to the limits of their free speech ideals.