Law may take all sorts of forms. In the U.S., it may take the form of a federal constitution or a state constitution, or of a federal statute or a state statute, or of a federal administrative regulation or a state administrative regulation, or of a federal court decision or a state court decision.
For example, with patents, you have a constitutional provision that empowers the federal legislative branch to authorize grants of limited patent monopolies, you have federal statutes dating back to 1792 that implement that authority by conferring rights on inventors to apply for and obtain patents, you have a regulatory framework under the USPTO that sets out a framework for evaluating what is or is not patentable, and you have federal courts that adjudicate disputes affecting the enforcement of patent rights. One can argue over whether patent grants are "property" or not but this is really more a philosophical argument than a legal one. Those who oppose patents philosophically will argue that patents are nothing more than monopoly grants that cannot be said to have equal dignity with tangible forms of property and that are therefore not worthy of the label "property." In this view, the "property" label has merely been hijacked by those who seek to unfairly skew the debate over whether patent monopolies should ever be granted in the first place. Yet, while this sort of discussion frames the philosophical debate, the law gives patent holders a full complement of rights that confer all the attributes of property: under indisputable governing law today, such rights can be owned exclusively by someone to the exclusion of all others, they can be licensed to others by the rights holder via a license in exchange for value given (fees or royalties, one-time or recurring) or otherwise, either exclusively or non-exclusively, they can be assigned, transferred, or sold for valuable consideration, they can be passed by inheritance in the case of individuals or sold out of bankruptcy court in the case of any holder, and each successive buyer of the rights has valuable, exclusive rights that certainly resemble "property" whatever the philosophical arguments pro or con in using that label. When the Nortel patents sell for several billion dollars on auction, or when Google buys Motorola for many billions of dollars when the main asset is its patent portfolio, the commercial players are buying valuable intangible assets, i.e., bundles of legal rights that can be possessed, used, improved upon, bought, sold, sued upon, and legally enforced to the exclusion of others. In every functional sense, that is "property" whether it is ultimately some fundamental right or not in the philosophical sense.
The same goes for copyright, which protects tangible forms of creative expression, whether writings, films, compositions, software code, or many other items. As with patents, the rights associated with legal protections of such creative expressions can have huge value and such rights can be "owned" by a specific holder to the exclusion of all others, can be licensed, sold, gifted, passed by will, etc. in much the same manner as can tangible forms of property. Such rights, then, in a legal functional sense, have all the attributes of "property" whatever they may be in a fundamental, philosophical sense.
The same goes for trademarks - a form of intangible right by which the law protects a merchant's right to use marks or symbols to identify the origin of goods or services so that others cannot fraudulently pass off their goods or services as those of another. Unlike patents and copyrights, trademarks have their origin in judicial decisions by which the courts decided to grant forms of "property" protection to protectible marks created by merchants while selling their goods or services in commerce. Later, federal statutes and regulatory structures were set up to facilitate more efficient registration of such marks. The result, though, is the same as in the case of patents and copyrights: trademark rights can be bought and sold, licensed, sued upon for enforcement, etc. in all the ways that tangible forms of property can be and in this legal, functional sense they are "property" as much as anything else can be called that.
So too trade secret rights are ascribed to commercial information that is both proprietary (i.e., "owned" by someone) and confidential and such rights similarly can be sold, etc., as in asset sales or stock sales by which entire companies are acquired.
At every level of law (federal and state constitutions, statutes, regulatory bodies, and courts), the foregoing forms of intangible rights are recognized and protected as "property." In the legal sense, then, IP is indisputably treated as "property" whether or not it is "fundamental."
SOPA is illegitimate not because copyrights are illegitimate by nature but because it seeks to take a reasonable enforcement scheme relating to copyrights across the web and turn it into a bastardized version that is grossly unfair and highly destructive. One can argue that copyrights are illegitimate by nature but that is a philosophical argument and not a legal one. Legally, copyrights have consistently been enforced in the U.S. since the adoption of the federal constitution. Are they always legitimately enforced? As a matter of policy, they have not been, in my view. The copyright extensions, the grabbing of public domain materials to put them back in copyright, etc. have been products of grotesque lobbying efforts and cravenly legislative efforts that serve no proper purpose other than to favor a privileged few in efforts that clearly damage the broader society (this is another way of saying they don't serve the legitimate purposes of copyright in the first place). That said, however, the core of copyright has a long and well-recognized place in American law and (I believe) broad significant support from the many people who believe that creative efforts should not be treated as common property but should be protected (within limits) for the benefit of their creators.
It thus seems to me irrelevant to say that IP is not a "fundamental" right (I would agree that IP rights are not fundamental in the constitutional sense). Yes, Congress could constitutionally act to repeal the implementing statutes. But so what? Copyright has been consistently implemented and enforced in the U.S. since the beginning of the nation and there is every reason to believe that it will continue to be protected as "property" in the sense I describe above for many years to come. Copyright may not be "fundamental" in the constitutional sense but it is deeply entrenched in our nation and (in my view) continues to have strong support among the broader public. One can support it while adamantly opposing SOPA. The two should not be confused.