Though a specific challenge has yet to arise, open source leaders are already planning the counter-offensive. One option is to fight fire with fire, by patenting open source innovations. This method has been proposed but is unlikely to take off. It could prove expensive and many free software fans are strongly opposed to the notion of software patents on principle. So there is intense pressure to back a different approach.
Patents tend to be interpreted in an extremely broad fashion by their owners.
A good defence in the courtroom is to deny infringement by finding evidence that the patent should be interpreted more narrowly. Gathering the proof is probably easier for an open source group than a corporation. This method has already scored one notable victory. In late 1997, Wang filed a suit against Netscape and AOL, claiming that it held a 1984 patent covering Web browsers. Netscape successfully argued that Wang's patent could not cover such a general case, by showing similarities between the Internet and systems that preceded Wang's application by decades.