Abstract: A display control apparatus (2000) detects, by using audio data including a sound around a display device (10), a first situation where target information being displayed by the display device (10) can be viewed by a person other than a specific person (30), or detects, by using image data including surroundings of the display device (10), a second situation where the target information being displayed by the display device (10) can be captured by a camera. The display control apparatus (2000) changes an output state of the target information in the display device (10) in response to detection of the first situation or the second situation. A change of the output state is processing of stopping output of the target information or processing of reducing visibility of the target information as compared with visibility before a change.

Abstract: A network apparatus (2000) includes a port (20). A target apparatus (10) is connected to the port (20). The network apparatus (2000) computes a communication feature value related to communication between the target apparatus (10) and the port (20). The network apparatus (2000) determines whether a communication feature value computed for the target apparatus (10) and a communication feature value predetermined for a specific apparatus match each other. The network apparatus (2000) performs predetermined control processing when it is determined that the communication feature value for the target apparatus and the communication feature value for the specific apparatus do not match each other.