It would not have happened at Threadneedle Street in Sir Montagu Norman's day. When Britain's first modern central banker was at the helm of the Bank of England between 1920 and 1944, tweeting was strictly for the birds.
The Group of Twenty Finance Ministers and Central Bank Governors (G-20, G20, Group of Twenty) is a group of finance ministers and central bank governors from 20 major economies: 19 countries plus the European Union, which is represented by the President of the European Council and by the European Central Bank.