From Project Disco:

Public Knowledge and the R Street Institute

Public Knowledge (“PK”) and the R Street Institute (“R Street”) made two arguments in their amicus brief. The first argument, based on the brief PK submitted in the Cisco v. Aristaappeal pending at the CAFC, was that the panel’s decision that APIs are copyrightable subject matter would potentially affect broad segments of the technology and software industries. Modern information technology relies on technical standards that set forth application programming interfaces similar to Java’s. Many of these technical standards are now at risk of copyright litigation based on the panel decision.

The second argument, based on an article written by R Street’s Charles Duan, was that the panel’s decision suggests that programming languages, and by extension human language, could receive copyright protection. APIs and human languages share basic characteristics at issue in the panel’s decision. Both employ a vocabulary of words with semantic meanings, as well as a syntax specifying how these words are ordered. In holding that Google’s implementation of the Java API constituted copyright infringement and not fair use, the panel “opened the door to the remarkable possibility that copyright infringement could inhere in everyday uses of language.”