The recent expansion of the Internet and e-commerce has led to many patents being applied for and being granted for business methods implemented in software and the question of whether business methods are statutory subject matter is a separate issue from the question of whether software is. Critics of the Federal Circuit believe that the non-obviousness standard is partly responsible for the large increase in patents for software and business methods. There have been several successful enforcement trials in the United States, some of which are listed in the list of software patents article.