"Industry made a public commitment to honor Do-Not-Track requests from consumers but has not yet followed through," Rockefeller said. "I plan to use this hearing to find out what is holding up the development of voluntary Do-Not-Track standards that should have been adopted at the end of last year.”
Rockefeller has introduced legislation that would mandate a Do Not Track option.
Many online advertisers install small tracking files on user's computers and then display ads based on the user's browsing history. Business groups warn that an overly restrictive Do Not Track standard could stifle online commerce and prevent websites from offering their services for free.
But privacy advocates argue that Internet users should be able to control access to their own personal information.