Not so easy, best option is to seceratly setup a DNS server, and setit up as there only DNS server. I'm sure it would be realy easy to change google.com to that goatse web site <removed explicit link>, then say "Well, obviusly google's been hacked" ^^, if they are the kind of people I think they are, they will run all over the place making compleate idiots of them selfs by claiming that google has been hacked. and then you can seceratly put it back at some point, but of course, you only have ot put it back on your DNS server, no client modifications needed.