NebuAd exploits normal browser and platform security behaviors by forging IP packets, allowing their own JavaScript code to be written into source code trusted by the Web browser. NebuAd and ISPs together cooperate in this attack against the intentions of the consumers, the designers of their software and the owners of the servers that they visit.... NebuAd breaks the rules of acceptable behavior on the Internet. It monitors what you do and see on the Internet, it breaks in and changes the contents of your private communications, it keeps track of what you've done, and if you even know that it's happening, it is impossible to opt-out of it."

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 probably illegal here too. The problem is that what Phorm and NebuAd do sounds a lot like wiretapping, and wiretapping is illegal under several federal laws. At least three federal laws govern when electronic communications providers can disclose their customers' communications to third parties. One of the key questions Declan looks at is consent: the law generally allows eavesdropping with customer consent, but the exact nature of the consent isn't clear. ISPs have tended to be very secretive about their use of these systems, so at the very least, privacy laws would require that ISPs disclose what they're doing and give consumers a way to opt out. But Declan suggests that this might not be sufficient. Some of the legal experts he talked to think the law would require the ISPs to obtain the affirmative consent of customers before commencing the use of these programs. Since it's hard to imagine customers being enthusiastic about having their ISPs eavesdrop on them, such a requirement might make these programs non-starters.