Hazelnoot@feditips if that thread is correct, then Mastodon's implementation of Authorized Fetch is broken. When it's working, attempting to access anything through a web browser should return a 403 / similar error unless you log in. That's also how it works on Pleroma and Misskey.
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.