If it scares you, by all means don't use it. It's that simple. You need to be much more concerned with using regular email. Most of us are more willing to discuss private matters via regular email but almost every major ISP has email monitoring systems in place. They can do a hell of a lot more than Google.
Read up on Carnivore, Altivore and of course Echelon
http://compnetworking.about.com/libr.../aa120400b.htm
If you have something private to discuss, the internet probably isn't the place to do it.