As we previously reported, Oracle America has filed suit against Google for (primarily) patent infringement. If you're not familiar with the case, I'll quickly summarize.
Oracle claims Google is in violation of seven U.S. patents previously filed by Sun Microsystems as part of the Java platform. Oracle now owns Sun. The alleged infringer, more specifically, is Android. If you want a more detailed explanation, read the next paragraph. If not, look at the pretty picture and continue.
The patents generally relate to the Java virtual machine (JVM). Apps on your Android phone run through the Dalvik VM (DVM), a Google / Open Handset Alliance developed alternative to JVM that utilizes portions of an open source Java implementation known as Apache Harmony.