Computer programs are constantly evolving, making copyright infringement an important issue. In 2010, Oracle filed a complaint against Google for copying API packages for its mobile operating system. The district court ruled in favor of Google, finding that APIs are not subject to copyright. On appeal, the circuit court endorsed the abstraction-filtration-comparison test for determining copyrightability. It found that certain expressions in Oracle's declaring code were original and protected by copyright. Google petitioned the Supreme Court to review the appellate court's decision, as a lot of money and reputation depends on the Supreme Court's ruling.