In the hands of the newly established Federal Circuit, however, this small scope for software patents in precedent was sufficient to open the floodgates. In a series of decisions culminating in State Street Bank v. Signature Financial Group (1998), the Federal Circuit broadened the criteria for patentability of software and business methods substantially, allowing protection as long as the innovation “produces a useful, concrete and tangible result.” That broadened criteria led to an explosion of low-quality software patents, from Amazon’s 1-Click checkout system to Twitter’s pull-to-refresh feature on smartphones. The GAO estimates that more than half of all patents granted in recent years are software-related. Meanwhile, the Supreme Court continues to hold, as in Parker v. Flook, that computer software algorithms are not patentable, and has begun to push back against the Federal Circuit. In Bilski v. Kappos (2010), the Supreme Court once again held that abstract ideas are not patentable, and in Alice v. CLS (2014), it ruled that simply applying an abstract idea on a computer does not suffice to make the idea patent-eligible. It still is not clear what portion of existing software patents Alice invalidates, but it could be a significant one.