A screenshot shows the Mastodon app on a mobile phone in Berlin, Germany, November 7, 2022. After six years' work by Eugen Rochko, a young German programmer, Mastodon was born of his desire to create a public sphere that was beyond the control of a single entity. For the most part, Mastodon looks like Twitter, with hashtags, political back-and-forth and tech banter jostling for space with cat pictures. Mastodon is installed on thousands of computer servers, largely run by volunteer administrators who join their systems together in a federation. With Twitter in disarray since the world's richest person took control of it last week, Mastodon, a decentralized, open alternative from privacy-obsessed Germany, has seen a flood of new users. REUTERS/Lisi Niesner