Last year a company called NebuAD started placing hardware on ISP networks that tracked user website visits, then used that data to deliver contextual ads based on those surfing habits. The endeavor didn't end very well. Since the system was thought to potentially violate wiretap and privacy ads, the entire idea imploded under Congressional scrutiny -- and most of the participants in the project now face lawsuits. In an act of bravery (or stupidity), Google now says they're jumping into behavioral advertising with both feet, despite the recent uproar:Google tries to explain the idea over at their AdSense blog, saying that the idea's currently in beta, with broader expansion planned for 2009. Google's privacy policy explains how users can opt-out of this new type of user tracking. Of interesting note is that Google is giving users some degree of control over what types of ads they'll see via a new ad delivery preferences portal.

You can expect Google's biggest enemies (AT&T, Comcast and Verizon), who are eager to engage in behavioral advertising themselves, to come out swinging on this subject later today, painting the search giant as the worst sort of privacy violator. Still, there are differences -- namely that Google is giving users some degree of control, and is being transparent about the plan (unlike many of the NebuAD-related ISPs were). We're also talking about a content provider users can choose not to use -- in contrast to an ISP you may be forced to use due to limited competition.

Still, there are legitimate questions and concerns here -- not least of which is why consumers should have to opt-out of anything, ever -- and whether Congress will pass a law requiring all such projects be opt in. The system's use of an opt-out cookie is also a nuisance for consumers who frequently delete cookies (though Google has apparently tackled this with a Firefox and IE plugin). Your thoughts?