1) Register a domain:whatever.com
2) Create a www subdomain, host a website on it full of criticism and insults against google.
3) Have the IP for "whatever.com" point to one of googles services.
4) User reports or looks up the ip address of the site they think they are on, and they think it's google.
It's too late on a friday night (hic!) to think properly, but I'm sure some evil could be done along these lines... even more effectively, probably, using the "m." bit.