hardware error
Election Procedures: Manual Recount
A number of states provide for a manual recount of a small sample of the ballots cast as a way to detect voting system errors. In California, although there is a requirement for a one percent manual recount, there are no rules on how this should be carried out. If not done carefully, however, the recount will not accomplish the task assigned to it. In particular, it may fail to detect election fraud committed by hackers inside or outside of the elections department.
