A US congressman unveiled plans on Thursday to introduce legislation that would bar companies from tracking the behavior of children online.

Representative Edward Markey, a Democrat from Massachusetts, said the bill would include a 'Do Not Track' requirement "so that kids do not have their online behavior tracked or their personal information collected or profiled."

He said he plans to introduce the legislation next year.

"For many kids today, the Internet is like online oxygen -- they can't live without it," Markey said in a statement.

"The Internet presents access to incredible opportunities to learn and communicate that were unimaginable only a few years ago," he said.

"But kids growing up in this online environment also need protection from dangers that can lurk in cyberspace," he said. "Children should be playing 'Hide and Seek' not 'Hide from the Creep.'"

Markey's announcement came a day after the US agency in charge of protecting the privacy of consumers endorsed a "Do Not Track" mechanism.

The Federal Trade Commission (FTC) preliminary staff report said industry efforts to address privacy through self-regulation "have been too slow, and up to now have failed to provide adequate and meaningful protection."

Its recommendations included the creation of a "Do Not Track" option, perhaps built into Web browsing software, which would signal online services not to collect surfing or ad-targeting data.

A US House of Representatives subcommittee on Thursday also held a hearing on the feasibility of creating a "Do Not Track" mechanism that would go beyond just children.

"Through such a mechanism, consumers could advise would-be trackers unambiguously and persistently that they do not wish to be followed by digital snoopers and spies across websites and their various fixed and mobile computing devices," committee chairman Representative Bobby Rush said.