"As explained in our brief, there are strong practical and legal arguments against software patents. It is increasingly accepted as settled by scholars that software patents impose enormous economic costs, including costs of litigation, that are not justified. All software developers face a risk that code they created without reference to a patent could nevertheless someday be argued to infringe patents unknown to them. With hundreds of thousands of software patents in the U.S., there is no practical way for anyone, including giant software companies, to rule out this possibility."
Source: http://www.redhat.com/f/pdf/written-statement-in-case-g.pdf