A new report from Twopcharts has found that 44% of the world's Twitter accounts have yet to send a Tweet. With approximately 974 million Twitter accounts, that's an awful lot of dead air. As the Wall Street Journal points out, however, this could mean that people, scammers, or bots simply signed up for an account and never came back—or that there are hordes of shy people out there waiting for the moment to strike. Do you have a Twitter account you have never used? If not, why not? More here.