Mata Hari and the Danish baroness Carla Jesse are among the most powerful women in the history of espionage. Carla Jesse's method was the kiss of death. She coated her lips with poison, and the German officers she kissed fell unconscious, whereupon their documents were stolen. However, retired espionage expert Erich Komorowski complained that it is extremely difficult to protect one's female agents with romantic involvements.