In late 2010, the Federal Trade Commission called on the ad industry to develop a universal and simple tool that would enable consumers to opt out of all online behavioral advertising.
Mozilla quickly rolled out a do-not-track header for consumers to activate. Turning on the header signals that users don't wish to be tracked, but ad networks can choose to honor it or not. Until recently, only a small number of ad networks said they wouldn't track people who activated the header.
Two weeks ago, the concept of browser-based headers got a big boost when the self-regulatory group Digital Advertising Alliance promised to require members to honor such signals.
Now regulators in Europe -- which has far broader privacy laws than the U.S. -- are weighing in on do-not-track. Jacob Kohnstamm, chair of the Article 29 Working Party, said in a letter to the Interactive Advertising Bureau Europe and the European Advertising Standards Alliance that a global do-not-track tool could satisfy the privacy law, but only "if users of all browsers have made an active and informed choice to allow or disallow the tracking."
EU regulators also say that honoring a do-not-track header requires companies to stop collecting data about users, including data that's only used for market research. The one exception is for "information strictly necessary to provide the service explicitly requested."
Kohnstamm also said that the IAB Europe's current self-regulatory plans -- which involving using icons to notify people about online tracking, and allowing users to opt out of online behavioral advertising -- don't satisfy an EU requirement that companies obtain users' explicit consent to tracking.
The Interactive Advertising Bureau's UK division said in a statement that it intends to continue working with regulators in Europe and the UK.