I'm one of millions who happily use Google's Gmail service to send and receive my email, even though the context-sensitive ads down the side of the screen are proof enough that Google's computers are monitoring every word I send and receive in emails (or write in this Blogger-hosted forum!)
Recent news is that Google plans to extend their powers of observation to the phone calls we make also: the new Google Voice service will provide a speech-to-text service for voicemail. Instead of having to listen to voice mail messages, they will be converted automatically to text as the Google computers listen in; the messages will then be sent to the subscriber by email, where they can be stored and searched.
Presumably, if they can do this for voicemail then the computers could listen to all my conversations, transcribe them and archive store for later search?
