A bunch of ISPs have been experimenting with systems such as Phorm and NebuAd that monitor their users' online behavior and create profiles that help third parties create more targeted advertisements.

Back in March we noted that behavioral advertising may be illegal under UK law.

And last week we reported that Congress was asking some tough questions about the plans.

CNet's Declan Declan McCullagh has an in-depth look at American law, and concludes that such systems are...