I am not a lawyer, but I don't think you need to be one to figure out why Oracle is doing this. Java and all its associated technologies are very valuable. Sun was never able to squeeze much money out of Java's IP (intellectual property). Sun preferred to make its money by building programs around Java.
Let's let James Gosling, Java's creator, tell you his take on how he saw Oracle thinking about making money from Java: "Oracle finally filed a patent lawsuit against Google. Not a big surprise. During the integration meetings between Sun and Oracle where we were being grilled about the patent situation between Sun and Google, we could see the Oracle lawyer's eyes sparkle. Filing patent suits was never in Sun's genetic code."
Why pick on Google first? Well, to quote some of my more cynical lawyer friends, you always sue whoever has the deepest pockets first. As Willie Sutton put it when asked why he robs banks, "Because that's where the money is."
Keep in mind that Oracle is headed by Larry Ellison, the dog-fighting pit-bull of technology CEOs. He'll take on any company at any time if he feels there's a chance that he can win. And Larry doesn't lose very often, as those of us who follow Oracle know so well.
If Oracle goes after other companies that use their own house-brewed Java, these businesses will be in for a world of hurt. Most of them can't afford lawsuits that may cost millions and last years. The whole secret of winning any lawsuit is being able to outspend and outlast your opposition. Few businesses have the resources fo fight a company the size of Oracle. Any resemblance between this strategy and that of many successful Survivor villains is not a coincidence.
I don't how this is going to work out. I do know that it has every potential to be a defining moment not just for Android or Java, but for open source in general. When I broke the story in November 2006 that Sun was open-sourcing Java under the GPLv2, I didn't notice that the Java specification patent grant that went along with it, and which came out in December 2006, is only valid if developers use fully compliant Java implementation. Oops.
If I were Google or any other company that has shipped Java spins-offs, I'd be worried. I have a sinking feeling that patent cases, such as this one, are going to be far more troublesome for Linux and open source than any of the bogus SCO copyright claims were.
As Eben Moglen, director of the Software Freedom Law Center, said at LinuxCon, the day before the Oracle lawsuit hit the fan, "Clarity in software patents isn't coming any time soon," and "Large number of organizations with patents are still hostile to the GPL."
Who knew that Oracle, which has been an open-source supporter, would turn this nasty towards other open-source companies? Well, from what Gosling has said, Oracle did. This does not bode well for free and open-source software.