Lawyers traditionally have conveyed legal expertise in the form of advice tailored to individual clients’ needs. This business model is reinforced by licensing and professional responsibility rules designed to ensure lawyers’ competence and loyalty to clients’ interests. An alternative model based on the sale of legal information in impersonal product and capital markets is challenging the traditional professional model. In this new world, legal information engineers would to some extent replace legal practitioners. This Article provides a theoretical intellectual property framework for the regulatory decisions that must be made as the two models collide. We show that traditional professional regulation inhibits full development of the new business model by prohibiting some of its practices and limiting intellectual property protection for legal information. We challenge this approach by showing how a fully developed legal information market could substitute for some of the protection that licensing and professional responsibility rules provide consumers without the current model’s negative effects of restricting the supply and raising the costs of legal services. We apply our analysis to some actual and potential markets in legal information.