The privacy debate has raged all year, from the halls of Congress to the forums of technology blogs. But while lawmakers are closely examining how targeting works, a California lawsuit may change the future of behavioral advertising as it stands today.

Sixteen plaintiffs have filed a complaint against NebuAd and six internet service providers, alleging that NebuAd and the ISPs committed illegal privacy and security breaches with regard to subscribers. If the plaintiffs win the class-action suit, it could mean all ISPs would be required to seek consent before selling information about customers' online activity.

"The plaintiffs are trying to draw the line much further to favor the consumers than the industry and even the consensus might dictate," attorney Bennet Kelley, founder of the Internet Law Center, told MediaPost.