The default is public. Usually, the users who choose “must log in” choose it either because they’re paranoid about privacy, or because it is a prerequisite to having the site enforce a viewer blacklist for them (to block incessant stalkers.)
There is also, above and beyond that, the ability to make a blog private, by setting a password to access it. A blog with a password is still rendered out to a static site, though, strangely enough; just one with the equivalent of an .htaccess password-gate behaviour.
There is also, above and beyond that, the ability to make a blog private, by setting a password to access it. A blog with a password is still rendered out to a static site, though, strangely enough; just one with the equivalent of an .htaccess password-gate behaviour.