Viacom, demanding $1 billion in damages, said that it had found more than 150,000 unauthorized clips of its material on YouTube that had been viewed "an astounding 1.5 billion times". YouTube responded by stating that it "goes far beyond its legal obligations in assisting content owners to protect their works". Since Viacom issued its lawsuit, YouTube has introduced a system that checks uploaded videos against a database of known copyrighted content as a means of reducing violations.