Employees also need to be trained not to allow other people to follow them through restricted access entrances. This social engineering attack, called piggybacking, can take place not only at the main entrance to the building but also at any internal locked doors, especially to rooms that contain computer equipment. Piggybacking may be attempted not only by outsiders but also by other employees who are not authorized to enter a particular area. Piggybacking often succeeds because many people feel it is rude to not let another person come through the door with them and they want to avoid confrontations. Role-playing exercises are particularly effective for increasing sensitivity to and skills for dealing with social engineering attacks.