Microsoft patent case comes under scrutiny in court

The US Supreme Court has pressed lawyers representing Microsoft in its efforts to bring about a change in existing patent law.

Microsoft has taken its case to the US Supreme Court to try and bring a change to existing patent law. Photo credit: Daniel Terdiman/CNET News

The software giant is fighting to overturn lower court rulings that it had infringed on patents held by i4i, a tiny Toronto company. Microsoft is hoping to create a precedent that would make it harder for companies with patent claims to prove infringement. Several large technology companies, including Apple, Google, Facebook and Cisco, have filed friend-of-the-court briefs supporting Microsoft's arguments. At the same time, i4i's case has drawn support from big pharmaceutical companies, venture capitalists, universities and the US government.

As the heart of the case is the degree to which companies accused of infringing have to prove that a patent is invalid. In the i4i case, the district court ruled that Microsoft had to provide "clear and convincing evidence" that i4i's patent is invalid. Microsoft wants the court to lower the standard, requiring defendants to offer only a "preponderance of the evidence" to invalidate a patent. This brief came under scrutiny in court on Monday, particularly with relation to legal precedents that seem to mandate using a higher evidentiary standard.

For more on this ZDNet UK-selected story, see Supreme Court queries Microsoft on patent law on CNET News.