Water has an exceptionally high heat capacity, I get it. But using drinking water to cool our servers (in the interest of seeing the very best ads) seems like an exceptionally short-sighted choice for us to make. If there is a less worthwhile thing for us to be doing with potable water, I can't think of it.
China recently is cracking down on golf courses in order to preserve water. I imagine the game of golf is not actually worth the cultural heritage and entertainment it provides if you want to think about the water it uses. At least the Chinese government has concluded this and it's facing a severe potable water shortage issue in the future.
http://www.cbc.ca/news/world/china-golf-water-land-shortages...
As well... water balloons and water guns? Baths as opposed to showers? The list goes on. Google's ads provide a service the general public finds useful.