Twitter: * single point of failure * one namespace for all users (remember how much AOL sucked? xXAllNamesAreTaken1998Xx) * the service is defined by its terse

Twitter: * single point of failure * one namespace for all users (remember how much AOL sucked? xXAllNamesAreTaken1998Xx) * the service is defined by its terse 140 character limits and the core use case would degrade if this was lifted. Silly article.