This excerpt taken from the ATVI 10-Q filed Feb 8, 2006.
Microsoft lntellectual Property. If Publisher learns of any infringement or imitation of the Licensed Trademarks, a Software Title, Online Content or FPU, or the proprietary rights in or related to any of them, it will promptly notify Microsoft thereof. Microsoft may take such action as it deems advisable for the protection of its rights in and to such proprietary rights, and Publisher shall, if requested by Microsoft, cooperate in all reasonable respects therein at Microsofts expense. In no event. however, shall Microsoft be required to take any action if it deems it inadvisable to do so. Microsoft will have the right to retain all proceeds it may derive from any recovery in connection with such actions.