 In May 1908, Lenin lived briefly in London, where he used the British Museum Reading Room to write "Materialism and Empirio-criticism", an attack on what he described as the "bourgeois-reactionary falsehood" of Bogdanov's relativism.Lenin's factionalism began to alienate increasing numbers of Bolsheviks, including his former close supporters Alexei Rykov and Lev Kamenev.The Okhrana exploited his factionalist attitude by sending a spy, Roman Malinovsky, to act as a vocal Lenin supporter within the party.