Marketers pitching junk food and sugary snacks to children online aren't restricted by the same rules that govern their counterparts in television. But a new report from consumer advocacy groups is urging lawmakers to set limits on how food companies can advertise to children on the web.

"While there are some rules for television, there are no rules when you move online," said Patti Miller, VP of children's advocacy group Children Now and a member of the Federal Communications Commission's Task Force on Media & Childhood Obesity. "We don't want to reduce junk food advertising to kids [on television] and then find that it has just moved to another platform."

Berkeley Media Studies Group, part of the Public Health Institute in Berkeley, Calif., issued the report, which will be presented to members of Congress and officials at the European Union.

"With social networking, marketers are getting the kids to create the ads and share them with their friends," Kathryn Montgomery, an author of the report and an American University communications professor, told Business Week. "It is incredibly sticky and it is viral. Regulators need to understand that."