Hotel 626 is a haunted house available only on the Web designed by the Doritos brand. Visitors are trapped inside the hotel. The program uses your webcam to sneak a picture of you. Until recently, one of the only ways to get out was to provide a crucial piece of personal information -- your phone number.
Doritos says it no longer collects phone numbers and insists that Hotel 626 is not aimed at children under 18. But it's not hard for, say, even a 9-year-old to fool around on the site. All the child has to do is lie about his or her age -- and he or she is in.
Chris Kuechenmeister, a spokesman for Frito-Lay, which owns Doritos, told ABC News the site's age-screening technology is also "commonly used by a range of other companies."
He added, "While we believe we have put effective control into place to properly screen visitors, we are always looking for ways to enhance the security of our consumers and Web sites."
Indeed, many food sites claim they are not for children. Coca-Cola says its "Happiness Factory" is aimed at kids over 12. But critics say their eye-catching, colorful games and graphics seem tailored to a younger audience.
Coca-Cola told ABC News it "does not market any of its products to children under 12."
ABC News tried to show some of these sites to Dan Jaffe, who lobbies for the advertising industry. He said he didn't want to talk specifics. He did say, however, that government and the industry itself had established a well-functioning system of regulation.
Asked whether the Doritos site that procured phone numbers went too far, Jaffe said, "I'm just not going to try and make that judgment. But I must say to you that we set up a system to deal with these types of issues."
He also downplayed any link between advertising and the epidemic of childhood obesity in America.
"We hear over and over again it's the advertisers -- 'Let's stop the advertising. If we only stopped the advertising the obesity rate would suddenly go down' -- I just think there's no data to suggest that," said Jaffe, executive vice president of the Association of National Advertisers.
But a major study by the Institute of Medicine says that "food and beverage marketing to children represents ... at best, a missed opportunity and, at worst, a direct threat to the health of the next generation."
David Ludwig, an associate professor at the Harvard Medical School and director of the Optimal Weight for Life program at Children's Hospital Boston, said, "The food industry wouldn't be doing it if it didn't work."
"The food industry loves to promote itself as a responsible corporate citizen -- a stakeholder, if you will, in the obesity epidemic. And while there are some more responsible entities in the food industry, overall they've been in the forefront of reducing nutritional quality for children to its lowest common denominator," he said.
The food industry also argues it is up to parents to keep an eye on their children, the Internet sites they visit and the video games they play.
Single mom Allison Paul says that is not always possible.
"I mean, he's 13 years old. What am I supposed to say to him, 'OK, sit down here and let me look at what you're doing at all times on the computer.' I mean it's hard," she said.
"As a mom who's trying to teach their children a healthy lifestyle, knowing that this is happening -- it's scary," Paul said.