NEW: Former 🇬🇧 UK Prime Minister Boris Johnson says he has “long suspected Bitcoin is a giant Ponzi scheme,” questioning who controls the network. “But Bitcoin? What is it? It’s just a string of numbers stored in a series of computers. Who controls it? Who is in charge?” “Who do we talk to if they decrypt the crypto? There’s no one except this Nakamoto, who may be no more real than Pikachu or Charmander.” 🤦‍♂️