Common law judicial action more closely harmonizes and tailors law for industries---state courts on trade secrets prove.

In an effort to harmonize the law across different states, some state legislatures have codified these common law intellectual property regimes.26 This process has impeded courts' ability to rely exclusively on case law as their source of rules. Nonetheless, courts continue to develop the law as needed, often independent of the statutes, and in the traditional, if somewhat attenuated, common law method. Courts work in tandem with legislatures in these contexts, retaining a secondary, but significant, role.

Second, the idea of intellectual property in these regimes is intricately connected to the concept of common law property. Common law property interests revolve around the idea of exclusion and use a variety of mechanisms to render it operational. 27 Since the common law process involves a bilateral dispute, common law property interests are ordinarily relational. In other words, they originate in actions alleging an interference with a pre-existing interest, and in adjudicating the interference, courts determine the nature and existence of the interest alleged to have been interfered with.

For long, the only reason the distinction between property and nonproperty interests mattered was that courts refused to grant injunctions for nonproprietary interests. 28 Once equity relaxed this rule, the distinction ceased to be of much significance. Many of what are today termed "common law property interests" originated in tortious, contractual, or quasi-contractual settings.29 They continue to be called "property" interests because they convey an ex ante possibility of exclusion in certain situations. Thus, trespassory action is ordinarily referred to as a property action even though exclusion is tied to a defendant's actions (that is, the wrong); the same is true of common law intellectual property regimes. The idea of "property" here is subsidiary to the context within which the interest originates, which tends to be either contractual (where rights and duties are determined by parties themselves) or tortious (where rights and duties are prescribed by law). In relation to trade, secrets, perhaps the most robust common law intellectual property form today, Justice Holmes famously remarked:

The word "property" . . . is an unanalyzed expression of certain secondary consequences of the primary fact that the law makes some rudimentary requirements of good faith. Whether the plaintiffs have any valuable secret or not the defendant knows the facts, whatever they are, through a special confidence that he accepted. The property may be denied, but the confidence cannot be. Therefore, the starting point of the present matter is not property . . . but that the defendant stood in confidential relations with the plaintiffs .... 30

In other words, the idea of property as used in the context of trade secrets is largely relational. The right to exclude originates in a very specific set of circumstances, and identifying these unique circumstances remains the law's principal concern. The same is true, in various shades, of almost all forms of common law intellectual property, often bringing into question their very classification as "property." The relational nature of these interests also reduces the social costs associated with exclusionary (that is, monopoly) control. Since exclusion operates only in a very limited set of circumstances, these regimes effectively minimize the static and dynamic inefficiencies traditionally associated with property rights in nonrivalrous and nonexcludable resources. 31