ELON MUSK, the world’s richest man, has described Twitter as the “de facto public town square”. On April 25th he struck a deal to take it private. Mr Musk, the boss of companies including Tesla, a carmaker, and SpaceX, a rocket firm, put together an all-cash offer worth about $44bn, stumping up the bulk of the financing himself in the form of $21bn in equity and a $12.5bn loan against his shares in Tesla. It amounts to one of the…