A method of activating security functions on a computer device, for example a mobile communications device. The computer device includes a device state that may be realized by way of a first user input or a second user input. The method includes designating the first user input to realize the device state as a security rule having an associated security function, detecting realization of the device state, and activating the associated security function if the device state was realized by way of the second user input rather than the first user input. For example, the first user input may be a shortcut input, and the second user input may be a conventional or normal input.