For almost two years Google has been bothered over and over by Oracle because, according to Oracle, Android infringes upon Oracle's Java patents. The trial is either expected to start this afternoon or on Tuesday, depending on how Monday morning's jury selection goes. Oracle is seeking royalties and damages from Android to the (minimum) tune of $32.3 million to begin with, with a percentage of new sales for the future.
Oracle originally had quite a few patents they claimed that Android infringed upon, but since August of 2010 when this all started those claims were tossed out. Currently there case is resting on two patents, and one is iffy and may possibly be thrown out soon. Also in the law suit is a request from Oracle that Google not be allowed to continue infringing upon Oracle's patents, meaning that Android could lose some functionality if Oracle wins the case.