WASHINGTON, DC – Add Kansas-based internet service provider Embarq to the list of companies from which Congress wants answers about Web-surfer-tracking practices. The company has been accused of using “deep packet inspection” to monitor the habits of its 1.3 million customers in 18 states without notifying them. The technology was provided by NebuAd, already in the feds’ sights for licensing its software to mostly small firms that say they want to improve the relevance of ads shown to surfers.Congresscritters, who admittedly know little about the technology that allows ISPs to read nearly every keystroke performed by a surfer as he or she wends his or her way through the wilds of cyberspace, have voiced concern that deep packet inspection may violate consumers’ rights to privacy. Because of its potentially intrusive nature, the practice has been likened to illegal wiretapping. Some consumer advocates and First Amendment experts say deep packet inspection very well may be illegal.

Consequently, the House Energy and Commerce subcommittee on telecommunications and the Internet has taken up the subject in formal hearings.

“Surreptitiously tracking individual users’ internet activity cuts to the heart of consumer privacy,” panel chairman Rep. Edward J. Markey [D-MA] said. “Embarq’s apparent use of this technology without directly notifying affected customers that their activity was being tracked, collected and analyzed raises serious privacy red flags.”

Deep packet inspection also has beneficial uses: Among other things, it is employed to detect viruses and to speed the routing of messages. However, the use of the technology to discern consumers’ buying, searching and surfing habits — not to mention the actual content of email, instant messages and internet phone calls — has privacy advocates crying “foul!”

Witness a comment from NebuAd Chief Executive Officer Bob Dykes while he addressed media and advertising executives in New York in February: “We see virtually every site that you go to. This gives us much greater reach, relevance and results for our advertisers. We actually see not only that you went to all these sites, we know what you did on the sites. For example, if you went to a travel site, we know that you’re looking to go to Las Vegas or the south of France.”

Dykes backed away from that statement a bit during a recent interview with The Washington Post. He told The Post his company doesn’t collect or keep “personally identifiable information.” Instead, he said, NebuAd encrypts a user’s details anonymously. The company also does not monitor email, IMs or internet phone conversations, he said.

“Our position is well-supported that we operate within the law,” Dykes told The Post.

Alissa Cooper, chief computer scientist for the Center for Democracy and Technology, begs to differ.

“This is an obvious privacy violation even when the eavesdropper does not know your identity,” she told The Post. “The issue we have is with the interception itself. We think people simply do not expect a middleman to be sitting between them and the websites they visit.”

Reps. John D. Dingell [D-MI] and Joe L. Barton [R-TX] want answers. They sent a letter to Embarq demanding specifics about its deep packet inspection practices and why it chose not to alert its customers about the snooping. A company spokeswoman told The Post Embarq is formulating an appropriate response.

Embarq is not the only ISP enjoying public scrutiny about deep packet inspection. In June, Charter Communications — the fourth-largest cable operator in the U.S. — backed out of proposed deal with NebuAd after customers objected to the plan.

Analysts suspect most internet users would object to being monitored at that level if they were informed and allowed to opt out.

“If you remind people that you’re tracking them — ‘Hey, I know that you recently started wearing medium T-shirts instead of large. Did you lose weight?’” might be more than just a bit off-putting for the average Web surfer, Emily Riley, an online advertising analyst with Jupiter Research, told The Post. “That’s creepy.”