The iPhone has already staked its place as a great achievement in aesthetic industrial design. Apple's billion dollar verdict against Samsung, in part for copying that design, signals the legal system will protect innovators from those who would copy another's efforts.

But lately, some courts have begun to accept a radical argument that the more successful an aesthetic design, the less likely it will be protected from copying.

In fact, even Samsung was allowed to make this argument to the jury, known in legal jargon as "aesthetic functionality," in its lawsuit against Apple. While Apple escaped with its rights to the iPhone design intact, every manufacturer's heart should skip a beat knowing that its best designs could be deemed too successful for protection by a group of twelve randomly selected citizens.

A product's design can be protected as "trade dress." The purpose of trade dress law, a branch of trademark law, is to protect consumers from confusion about what company is behind the product. Trade dress is like a brand name or logo but in the form of product packaging or design.

That means trade dress will protect only unique, distinctive aspects of a product design that tell the consumer who makes it. Examples of protectable trade dress include the shape of a Ferrari Daytona Spyder, the Big Bertha golf club, and Nabisco's Goldfish crackers. In Apple v. Samsung, Apple successfully claimed rights in the iPhone's rectangular design with rounded corners, flat clear face, large display screen, black borders, metallic bezel and other features.

Trade dress has never protected features that have only a utilitarian function. This is because, unless a product feature is so novel that it deserves patent protection, functional features should be free for everyone to use. Ferrari can own the exclusive right to cars with distinctive shapes but not the exclusive right to cars with four wheels. Nabisco can own goldfish-shaped crackers but not crackers covered with salt. Apple can be the exclusive maker of iPhones but not all phones with touch screens. This concept is known as "traditional" or "utilitarian functionality" and is not controversial.