I've wondered how Twitter would have been different if they'd taken a similar approach: $1 per account per year. They'd certainly be smaller than they are now, but I suspect they'd still be bringing in several hundred million a year before going the advertising route--the pursuit of which seems to be at the root of a lot of their questionable product decisions over the last few years.

None of that's directly relevant to the article, of course, which is implicitly about better filtering tools. I continue to be kind of bemused that this is so difficult for modern services to figure out, given that LiveJournal essentially figured it out fifteen years ago. Yes, the two services aren't directly comparable, but it wouldn't be wildly difficult to offer controls over, for example, who's allowed to @mention you.