Google has bid on Nortel's patent portfolio. Kent Walker blogs about how they intend to use those patents if they acquire them.
http://googleblog.blogspot.com/2011/04/patents-and-innovation.html

"If successful, we hope this portfolio will not only create a disincentive for others to sue Google, but also help us, our partners and the open source community-which is integrally involved in projects like Android and Chrome-continue to innovate. In the absence of meaningful reform, we believe it's the best long-term solution for Google, our users and our partners."