The vast amount of information freely available on the Web constitutes a unparalleled resource for the automatic knoweledge discovery and learning. In this paper we propose a study on Ontology Induction for individual laws based on corpora comparison that exploits a domain corpus automatically generated from the Web; in particular we present a case study on the Italian "legge bassanini" (59/1997, 127/1997 - concerning the simplification and decentralization of administrative procedures). We evaluate how the induced ontological characterizations might vary according to different factors, such as the genre (e.g. news vs. social media),the learning algorithm, the text analysis granularity, etc; the main contribute of the paper consists in highlighting the structural difference emerging from the learned predicates and in showing how the learning mechanism might provide valuable information on how laws are perceived at different layers of the civil society.