Did you even read parent's post? We all agree that google (and yahoo, and hotmail) parse our emails to offer better ads and to index them for search. What we're talking about is bad employees reading your emails for their own curiosity.
This is getting off-topic, but did you forget about AT&T's secret rooms that were recording internet traffic? It's not just Google that wants to read your mail. Governments want to spy on their citizens, and ISPs are (allegedly) cooperating in the effort.
http://www.wired.com/science/discoveries/news/2006/04/70621
http://en.wikipedia.org/wiki/NSA_warrantless_surveillance_co...
http://en.wikipedia.org/wiki/Carnivore_(software)