Copyrights protect expressions of ideas, but not the ideas themselves. Anyone can write about two young lovers from different families and different backgrounds and not fear getting sued by the estates of William Shakespeare or Arthur Laurents or anyone who writes daytime TV movies. It is for this reason, that software can be reverse engineered to learn the ideas it embodies without violating the copyright, as long as the code is not copied and used commercially. The first lawsuit verdict that enforced this idea was Atari Games v. Nintendo in September 1992.
Nintendo tightly controlled access to its successful NES video game system and did not release the specifications for creating a game cartridge for the system. In order to produce a game for the system, companies had to pay a license fee to Nintendo and had to agree not to produce the licensed game for any other game system for two years. Incorporated into the Nintendo NES system was a computer program called 10NES that checked whether a particular game had been licensed. If not, the game was not allowed to run. Atari reverse engineered the 10NES program and created its own program called Rabbit for bypassing 10NES. Atari sued Nintendo for, among other things, unfair competitions and monopolistic practices. Nintendo countersued for, among other things, copyright infringement. The U.S. Court of Appeals ruled that the reverse engineering was perfectly legal. It also ruled that Atari infringed on Nintendo’s copyright when Atari created its own program based on Nintendo’s program. The decision by Judge Randall Rader reads as follows:
The district court assumed that reverse engineering (intermediate copying) was copyright infringement… This court disagrees. Atari did not violate Nintendo’s copyright by deprocessing computer chips in Atari’s rightful possession. Atari could lawfully deprocess Nintendo’s 10NES chips to learn their unprotected ideas and processes. This fair use did not give Atari more than the right to understand the 10NES program and to distinguish the protected from the unprotected elements of the 10NES program. Any copying beyond that necessary to understand the 10NES program was infringement. Atari could not use reverse engineering as an excuse to exploit commercially or otherwise misappropriate protected expression.