Stumble upon something interesting

[hot_pastrami]

For a few days I've been using a free browsing utility called Stumble Upon, and it's led me to some nifty stuff on the Internet. When you first sign up, you select from a list of general interests, and it builds a basic profile. It then adds a toolbar to your browser which allows you to "Stumble" to a URL which was enjoyed by someone with similar interests, randomly selected from their large database.

The toolbar also allows you to rank any page you visit with a score of "I like it" or "Not-for-me," and using this feedback, the application utilizes machine learning to narrow down your interests, so the "stumbles" become more and more accurate when guessing what you might like. Also, if you select "I like it" for a URL which is not in their database already, it is added to their database, and users with interests similar to yours might stumble upon it later. It basically uses highly accurate word-of-mouth to refer you to pages you might like... and it's accuracy is very good once it has enough feedback from the user.

My one worry about this utility is that they basically create and store a very clear picture of your interests and web surfing habits, which has the potential for abuse. Supposedly, it only makes note of those URLs for which you click "I like it" or "Not-for-me," but thet's still a lot of info which certain parties might find interesting, including law enforcement. Here is what their privacy policy says:

StumbleUpon may share aggregate information about its userbase with advertisers, business partners, sponsors, and other third parties; however, we will not share personally identifiable information that is not already available on your profile page with any third party without your express consent. For example, we may disclose how frequently the average StumbleUpon user clicks "Stumble", or how many users are signed up for a given interest. Please be aware, however, that we will release specific personal information about you if required to do so in order to comply with any valid legal process such as a search warrant, subpoena, statute, or court order.

It's a highly spiffy utlity which has led me to very interesting content I might not have found otherwise, but I wonder if it's continued use is worth the privacy risk. I don't visit any sites with the potential to get me into trouble (other than the Cellar, I mean), but I am concerned all the same. But could anyone glean any more useful information from that profile than they could by, for instance, combing through my message board postings?

I did a few quick stumbles against my profile just now, and got the following by way of examples... all of them are relevant to my interests:

http://www.winehq.org/site/about
http://www.placesforwriters.com/
http://www.freephotoshop.com/html/downloadables.html
http://www.privacyinternational.org/bigbrother/ (ironic!)
http://welcome.to/mytrailerparkpage (funny, but fucked up)

My bookmarks folder has grown quite a bit in the past few days... and I think our Link of the Day thread might suffer the same fate.

Incidentally, the toolbar works in IE, Mozilla/Firefox, and Netscape.