I use a login. (Because I am primarily checking messages and notifications.) I cannot access that MadisonAudubon page at all without signing up or logging in. Apologies as I should have realised that the discussion was about retrieving "public" profiles/pages without being logged in. I seem to recall a time when that was universally possible but at some point, quite some time ago if I remember correctly, it started to become limited. I would imagine the reason public pages are created on Facebook is to gain access to Facebook users, who are more heavily surveilled than non-users. Public websites like https://madisonaudubon.org could mirror the content they post on Facebook. In practice, this never happens. Calling Facebook a "walled garden" is misleading. It may be "walled" but there's nothing garden-like about it.