P3P is designed to allow Web browsers to determine if a site meets users' privacy expectations. W3C, which worked on the development of P3P, has officially endorsed the current version as the standard that Web sites and users should adopt.
But some privacy experts scoffed at P3P. "Consumer and privacy organisations have not been enthusiastic about P3P," said Marc Rotenberg, executive director of the Electronic Privacy Information Centre.
"I think it is certainly true that a lot of well-intentioned, smart people have been working on this for a long time. But to make it work for consumers, it has to be easy, effective and enforceable - three Es for the three Ps. As P3P now stands, I don't think it passes that test."
P3P is simple to use: A user can install the technology onto a computer and choose the level of privacy he wants. As the user surfs the Web, sites that use P3P indicate to the Web browser what level of privacy protections they offer. If a Web site does not adhere to the level of protection already chosen by the user, he is given a warning and allowed either to override the protection or to move on to a different site.
The W3C is aware of the criticism but said that P3P is just one part of a larger effort to ensure privacy on the Web.
A number of companies, including Fidelity Investments, have endorsed P3P and begun to use it on their sites, according to the W3C.