There is a lot of good blogger analysis about Google's ability to drill down deep into the search world and possibly get into trouble by not keeping personal privacy data private.
Given Google's business model of matching people to ads, it is in their best interest to not blow this, and keep private data private.
However, there seems to be a small group of alarmists raising issue with Google's recent purchase of RSS service provider Feedburner.
I do have to disclose that I am a big fan and happy customer of Feedburner. Congrats to the team over there.
Based on my above assertion that Google must, if they want to be successful, protect privacy, that this new found very rich data in Feedburner will get the same high-level of protection.
Plus, I don't see any signs of Google behaving badly, and that can not be said about ISPs.
Wired recently published a piece that outlines one of my big privacy concern areas - the data ISPs can and will be collecting, and what they plan to do with it as it effects public disclosure (overt, covert, and stolen), and possible manipulation as it enters 'their' network and gets to your devices.