1. A method for automatically changing information originating from at least either of a first user and a second user by using a mobile device, comprising steps of: (a) a first mobile device of the first user searching at least one second mobile device of at least one second user as a target to perform a specific interaction within a predetermined distance therefrom or searching at least one second mobile device connected to an AP, an ad-hoc network, or a base station of a cellular network to which the first mobile device is connected and then selecting at least one specific second mobile device among the searched at least one second mobile device to change the user-originating information; (b) the first mobile device transmitting to, or receiving from, the specific second mobile device data related to a specific interaction, if a specified touch gesture is detected in the first mobile device; and (c) at least either of the first and the second mobile devices allowing a server to update the information originating from at least either of the first user and the second user stored in the server or a storage device interacted with the server by referring to the transmitted data related to the specific interaction.