Orwell
George Orwell's aunt was an early proponent of Esperanto. When he went to stay with her in Paris, she insisted on speaking this new language.The political element of Esperanto particularly disturbed Orwell. He believed that an attempt to control and direct language was a defining feature of totalitarianism.
Newspeak - the language Orwell created for his dystopian novel, 1984, is clearly a variant on Esperanto.
More on Esperanto here
