The official Twitter account for the US National Security Agency (NSA) issued the following innocent-looking tweet on June 20 last year. On August 17, the same theme was taken up again: The 1st telegraph communications exchange occurred between Queen Victoria and President Buchanan in 1858. As part of a sequence of 12, the tweets are now claimed to be a coded back-channel used to communicate with a Russian who was negotiating to sell to the NSA a set of cyberweapons stolen from it in 2016 by a group called The Shadow Brokers.”]