Paradoxically though it may seem - Dark Matter should be dark, after all - one of the most promising signals that could reveal elusive fingerprints of Dark Matter is the analysis of the gamma-ray photons collected by the Fermi Large Area Telescope. After subtraction of the astrophysical background, gamma-ray data reveal the existence of a bump compatible with Dark Matter annihilation. In this talk I will give a general overview of this topic. First, starting from raw data, I will discuss the astrophysical origin of the signal. Then, I will outline possible implications for Dark Matter model builders.