Your right they have been spending big chunks of late (I believe the Motorola deal recently closed so that 12B check had to clear the bank eventually).
I continue to believe that Google is perceived to be a 'high value' target by offensive litigators.
Google doesn't have > $100B in the bank (citation: http://finance.yahoo.com/q/bs?s=goog+Balance+Sheet). You are probably thinking of Apple.