Photometric light curves show apparent spot concentrations separated by 180 degrees in longitude that are commonly referred to as active longitudes'. These spot concentrations have been observed to change in strength resulting in the flip-flop’ effect. We use a simple analytical model to calculate the light curve of a star with an arbitrary spot pattern to show that `active longitudes’ are a likely consequence of the limited information content contained in a light curve. We also show that the same effects apply to heavily spotted stars.