I'm continually amazed by Google's (NASDAQ:GOOG) Teflon jacket, both on Wall Street and in the popular press. When Google sneezes -- even if it sprays us right in the face -- we say "God bless you," and offer up a tissue.

The latest world-beating effort is Google's new deskbar, which was hailed -- even in our own pages -- as yet more proof that the upstarts know more about what people want than Mr. Softy does. The idea is that it will snoop around your hard drive, sniffing through files for clues, and then automatically figure out what you're interested in and deliver Web content to your computer -- while using this information to cook up targeted ads when you run a Google Web search.

Am I the only one who thought this just sounds like a fancy description for socially acceptable, opt-in spyware?

Whatever. I figured I'd take it for a spin. Sure, I was amazed (and a bit freaked out) after I installed the thing and it gathered stock quotes from tickers I frequently access. But after a few more hours' use, it was clear to me that Google's prying algorithms knew me as well as that old drinking buddy I see at Lee's Liquor Lounge once every three years. Worst of all, Google's deskbar is just as discreet.

When I arrived this morning, the "Photo" module was displaying a cheesecake picture of some tarted-up teenager clad in hot pants and a feather boa. (Admittedly, some people may consider this more of a feature than a bug.) It came from some Web page I don't remember ever visiting before in my entire life. For the first two hours of my work day, "Web Clips" displayed a headline containing a four-letter word that describes what you find on the ground at the south end of a northbound cow. I'm glad I work at a place where people wear jester caps and flip-flops.

I did a bit of tech sleuthing to try to comprehend exactly why the deskbar would have guessed that I'm interested in jailbait girly pictures from one of the offending websites. Brushing aside the (not unreasonable) hypothesis that anyone connected to the Internet must be interested in cheesecake pics, I could only find the following: a single cookie file from a celebrity gossip site, dated 11 months ago.

Weirder yet, after I specifically instructed this thing not to troll the cheesecake website for photos, it decided to download "photos" from some of the newspaper websites I frequent, including the flagship front pages of The Washington Post (NYSE:WPO) and The New York Times (NYSE:NYT). The image that's currently decorating my screen? A miniaturized rotating banner ad featuring what looks like a Starbucks (NASDAQ:SBUX) mochaccino.

Subtle, Google. A quick search shows that the coffee-hawkers are indeed purchasers of Google keyword advertising. I'm sure that's got nothing to do with that rotating banner ad. Or does it?

Let's face it: Microsoft (NASDAQ:MSFT) could never get away with this kind of thing. That's because everyone already loves to hate Microsoft, while Google's still considered an anti-Microsoft, a non-evil alternative. Among tech companies, Apple (NASDAQ:AAPL) shares a similar sort of "do-no-wrong" acceptance in the popular consciousness, but I think Google's upstart days are numbered.

Growing as quickly as it is, commanding so much of the online advertising market (15%, versus Yahoo's (NASDAQ:YHOO) 13%, according to a recent report), the company has already raised the hackles of privacy freaks, as well as the French. I don't know where the line is, but I do think there is a limit to how much power consumers will want to grant a single company, especially one that aims to earn its pay by piggybacking advertisements onto its capabilities as the world's premier data collector. Shareholders who currently think that the sky's the limit might want to at least consider alternative scenarios.

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Seth Jayson will be uninstalling Google's desktop bar by the end of the day. At the time of publication, he had positions in no company mentioned here. View his stock holdings and Fool profile here. Fool rules are here.