• by Wendy Davis , Staff Writer @wendyndavis, March 25, 2013

The Interactive Advertising Bureau and Association of National Advertisers are bashing Mozilla's plan to start blocking third-party cookies by default in the next version of Firefox. But not everyone is rushing to condemn Mozilla.

The Online Publishers Association, for one, doesn't seem to view the move as all that threatening. The publishers' organization says that the cookie-blocking plan “does not spell disaster for the advertising and publishing businesses.”

That's not to say that the OPA is enthusiastically endorsing cookie-blocking. Instead, the OPA says the plan “sheds more light on the need for an ecosystem-wide solution.” The trade organization adds: “A group like the W3C (World Wide Web Consortium), with the cooperation of the industry, including the OPA, has the potential to develop a balanced approach that will preserve consumer trust. ... Ultimately, this is about fostering a healthy environment where consumers feel safe online.”

In other words, the OPA takes the position that Mozilla's move could result in new, industry-wide policies about how to respect users' preferences regarding data collection and use.

For two years now, the W3C has been trying to come up with a standard to implement consumers' privacy decisions. But so far, the group hasn't reached any sort of consensus about how to interpret do-not-track requests that users send via their browsers -- despite the fact that all of the major browser manufacturers now offer do-not-track headers. (Those headers don't actually stop tracking. Instead, the headers signal ad networks and publishers that users don't want to be tracked; ad networks and publishers then make their own decisions about how to respond.)

Mozilla's decision to block cookies in Firefox appears to stem directly from the lack of progress in W3C. Jonathan Mayer, a privacy advocate participating in W3C, wrote the cookie-blocking patch. When he announced late last month that Firefox 22 would include the patch, he also said that cookie-blocking could be relaxed in the future for companies that agree to honor do-not-track signals.

But even though Mozilla clearly hopes to give consumers more control over their data,  no single technological change can in itself settle contentious policy questions. After all, if ad companies can't access third-party cookies, there are other ways to collect information -- like device fingerprinting. Given that no law currently prohibits companies from collecting data about Web users' activity, it seems inevitable that ad tech companies will turn to device fingerprinting, or other forms of tracking, once cookies become unavailable.