Further increases in the difficulty of importing to a secure domain digital content including watermarks which impose a degree of difficulty on illicit importing to the secure domain of the digital content is disclosed. Further increases in the degree of difficulty are necessary because the degree of difficulty associated with the watermarks is capable of being illicitly overcome by dividing the digital content being imported into segments that are so short that the watermarks cannot be reliably detected. In a recorder, recording is prevented by determining that adjacent activations of start and stop keys are such that the digital content has been so divided. In a playback unit, playback is prevented by determining that recorded sections are so short that the watermarks therein cannot be reliably detected.