The US Congress is to consider passing legislation to prevent American firms from collecting data to build profiles of people's web surfing habits.
The proposed law is still in draft form, according to reports from Associated Press.
Rick Boucher, chairman of the House Energy and Commerce Subcommittee on Communications, Technology and the Internet, is drafting the bill.
The move comes days after a coalition of 10 privacy campaigners, led by the Center for Digital Democracy, published a 13 page report on online behavioural tracking and targeting concerns and solutions.
The coalition said entities that capture web behaviours "seek to create, compile, and use detailed profiles revealing consumers' interests, activities, and other personal characteristics without limit", mainly to increase response rates to advertising.
"Without controls, profiles can and will be used for commercial, governmental and other purposes in ways that may harm consumers," it said.
The advertising industry and the Federal Trade Commission have published codes of behaviour to regulate behaviour profiling, but privacy activists remain concerned.
In the UK, a behaviour profiling firm, Phorm, conducted secret tests of its technology with BT. The resulting controversy led the department of business, innovation and skills to endorse its use only under tight conditions.
These include a requirement that potential advertisers publish explicit details of what information they would collect and how they would use it. Consumers would have to read it before opting-in to receive advertising based on the profiles that Phorm built up from the websites they visited and the apparent interests their visits disclosed.
Advertising industry spokesmen have rejected opt-in mechanisms as preventing consumers from getting what they want more efficiently, and as curbs on their freedom of commercial speech.
However, the European Commission has also raised concerns about the effect of uncontrolled data collection on users' privacy. Speaking at a conference in data collection and profiling in March, consumer commissioner Meglena Kuneva said: "Consumer rights must adapt to technology, not be crushed by it. The current situation with regard to privacy, profiling and targeting is not satisfactory."
The European Data Protection Supervisor has made developing a position on profiling a priority this year.