A communication terminal, a system, a method, and a control program stored in a non-transitory recording medium for controlling capturing of an image, each of which displays, on a display of the communication terminal, an image based on image data to be shared with a counterpart communication terminal; receives an instruction to prohibit capturing of a screen that includes the image based on the image data; and transmits, from the communication terminal to the counterpart communication terminal, information related to the instruction to prohibit capturing of the screen.