ClickZ: Google Responds to Gmail Privacy Concerns
The Register: Google mail is evil - privacy advocates

It could be quite useful if Google would keep a permanent record of everything searched and everything read in the new Gmail in boxes. Ads could become usefully relevant. But this isn't about to happen. When Google serves me an ad for SEO services while I read the latest rants about Google in search discussion lists, it won't even keep a record that it was anonymous user #2346923474. Bummer.

Alas, the privacy extremists worry about Google coming to know individual "state secrets" - ones that could potentially be easily subpoenaed by governments. When Google runs Orkut, the social network that necessarily identifies an individual, its browser cookie and the general Google one together can pin specific people to all of their web behavior and writings.