10 months ago, Oracle filed a lawsuit against Google based on Android's use of Java. A filing on behalf of Google shows just what they're up against with Oracle. So what are Oracle demanding as compensation? Not only are they looking for a licencing deal where they could receive a per-copy royalty. They have also indicated that they want a cut of Google's advertising revenue from mobile searches as part of the deal.
Florian Mueller provides an excellent analysis of this document, pointing out that Google's biggest mistake may have been in rejecting the terms of a potential deal with Sun Microsystem, before they were bought out by Oracle. As stated in the document:
He ignores Google's actual negotiation history with Sun regarding a Java licence for the mobile space, which would have included far more than the patents-in-suit and during which Google rejected a proposal to pay Sun <blacked out>
If Oracle were successful in these demands is would be a serious blow for Google's successful mobile business, requiring them to rethink how the model works.
Here's the document in full, Google's response to a filing from Iain Cockburn, a damages expert hired by Google. This is someone who Google feel would prejudice Google were he allowed to testify his conclusions in court and claim his report is "unreliable, misleading and inappropriate for presentation to jury".