Given the crisis Twitter is going through, I want to like Mastodon. But after a few days trying out the alternative social network, I expect mainstream Twitter refugees will struggle to make it a safe haven. Mastodon is a microblogging site that German programmer Eugen Rochko began creating in 2016 because of dissatisfaction with Twitter. Some aspects are similar, like the ability to share a few sentences of text and photos with your followers. What's different is its "federated" design, with thousands of interlinked quasi-independent services instead of one single social site. But one person's federation is another person's fragmentation....