Disclosed are a display apparatus and a method for preventing divulgence of image data thereof which may prevent image information including image data photographed by a camera of the display apparatus from being divulged by hacking, etc. The display apparatus includes a camera which captures an image; a display which displays the image thereon based on image data captured by the camera; a communicator which communicates with an outside of the apparatus through an Internet; and a controller which transmits image information including the image data captured by the camera, in the form of a transmission packet including the image data and a detection mark or indicator capable of detecting or indicating that the image data is to be transmitted to the outside, when the image information is to be transmitted to the outside through the communicator.