I run brick.do, which lets anyone publish anything. It’s basically a WYSIWYG pastebin with support for subdomains, nested pages, CSS, and JS. All your posts are disconnected from each other unless you explicitly decide to claim authorship — that is, by default nobody can discover than posts/sites A and B are by the same author. We also don’t divulge authorship information to anyone. We’ve been threatened with lawsuit…
Have a look at telegra.ph for how it probably should work, maybe require the login to publish to the public in the end.