These pirates were in most cases prominent local landowners or coastal residents with privileges such as Jinin or Jugonin (purveyors to the imperial household) that were pirating when not conducting their usual commercial activities and were difficult to control with only the power held by the Kokuga.
これらの海賊は、有力な在地領主、神人・供御人の特権を得た沿岸住民などが経済活動の合間に略奪しているケースが多く、国衙の力だけでは追討が困難だった。