And just like that, without a warning, Twitter changed policies again, and you now need a Twitter account and be logged in to see public tweets: Twitter has started blocking unregistered users (The Verge). Though I learned it first via Mastodon, of course. For example, this is what happens when you go to twitter.com/wikipathways: Fortunately, WikiPathways does have a Mastodon account, that anyone can see without having a Mastodon account.