Google's Creepy Advertising Technology

This post has nothing to do with Ray or religion--we all need a break from that, right?--but I wanted some feedack on something...

If you use Google Mail through the online interface (rather than downloading it into Outlook), you have probably noticed the ads and the way they sometimes match up with the content of your messages. What's happening here is that Google has automated search software that--

1) Rapidly scans the text of all your email messages
2) Searches the terms and compares them to a list of advertisements that companies have bought from them.
3) Finds a crude match...for instance, if you have the word "car" in an email, the search software might find an ad for used car or car repairs.
4) Publishes the ad based on the target word in your email message

I was always vaguely uneasy about it, but two experiences recently creeped me out and angered me. I describe these two cases below, and would like your thoughts on them.

• A friend of mine sent me a message about a mutual friend of ours who was recently and very suddenly diagnosed with a rare and serious form of cancer. Google displayed an ad in which that person's name was tied to an ad. I won't use his real name, but it would be as if his name were Treo and an ad for Sony’s Treo popped up.
• The automated search went through a message I had from the Obama mailing list and then it put up ads for other left-of-center political groups, publications, etc.

Sure, this technology is really convenient, but isn’t it also creepy? These weird, invasive dips into my private life—my relationships with friends and my political affiliations—are unsettling, even if no human ever accesses them. I’m going to read up on the technical details about how this advertising works. Maybe I’ll come away with a better feeling about it, but if advertising needs to create positive feelings about a product, Google ads are driving me away from products I see there.