The pirates that Sumitomo restrained through persuasion and martial arts were toneri (servants) of the Fugo-so (the upper class) from around the Seto Inland Sea, who had been laid off due to institutional reform by the Imperial Court with the aim of claiming vested interest in tax revenue that was sent to the capital.
純友が武芸と説得によって鎮圧した海賊は朝廷の機構改革で人員削減された瀬戸内海一帯の富豪層出身の舎人たちが、税収の既得権を主張して運京租税の奪取を図っていたものであった。