Civil liberties group the Electronic Frontier Foundation (EFF) has asked the U.S Supreme Court to overturn a patent ruling, saying the way a lower court views patentable inventions could hurt open source projects.

The EFF filed a brief asking the Supreme Court to shoot down the so-called "suggestion test," a method the U.S Court of Appeals for the Federal Circuit has used to determine whether an invention should be obvious to others, and therefore, not patentable.

The appeals court, in several cases involving the combination of inventions, has declined to invalidate patents for obviousness, except when the court can find evidence of an earlier "suggestion" that the inventions could be combined.

The EFF argues the suggestion test makes it too easy to convince the appeals court an invention isn't obvious. The appeals court has forced district court judges to abandon their own scrutiny and "leave their brains at the courthouse door," EFF lawyers wrote in the brief filed in a gas-pedal patent case called KSR International v. Teleflex, which the Supreme Court has agreed to review in the coming year.

The suggestion test "has forced litigants to search through haystack upon haystack of technical knowledge for the exact needle in which someone, somewhere, bothers to state the obvious," the EFF continued.

The suggestion test has contributed to a "massive surge" in the number of patents granted, EFF lawyers wrote in the brief, made public Wednesday.

The suggestion standard especially threatens free and open source software (FOSS) projects, because they are created in the open, making it easier for others to steal the ideas and file patent claims, said Jason Schultz, an EFF staff attorney.

In addition, many FOSS projects don't have the financial resources to defend against patent claims, Schultz said. "In fact, the economic margins of many FOSS projects are so thin that the expensive legal costs associated with both acquiring or defending patents would, quite simply, put the projects out of business," the EFF wrote.

FOSS projects also tend to be loosely organised, and email or message-board documentation may often not meet the evidence standards demanded by the appeals court, the EFF said.

"FOSS projects are less of a unified thing than most proprietary software companies," Schultz added. "They are scattered around and it's harder to track people and documents down sometimes."

FOSS advocates aren't alone in the tech industry in questioning the suggestion test. Microsoft and Cisco were among the companies signing on to an earlier brief arguing the appeals court has been "too lenient" in accepting patents. The suggestion test hurts innovation by forcing companies to spend their resources on "defensive, large-scale patenting," the companies argued.

But others dispute that patents are too easy to obtain. Getting a single patent can cost thousands of dollars, said Stephen Wren, an independent inventor from St. Louis. "My experience for the last 15 years has been that if anything patents are too hard to get, not too easy," he said.

Large tech companies are trying to make it even more difficult for small inventors, he added. "This is but another effort by large multinationals and their henchmen parading as public interest groups to gut the patent system," Wren said of objections to the suggestion test.

"They aren’t trying to fix it. They’re trying to bury it."