http://www.ftc.gov/opa/2006/11/zango.htm
"Consumers' computers belong to them, and they shouldn't have to accept any content they don’t want," said Lydia Parnes, Director of the FTC's Bureau of Consumer Protection. "If consumers choose to receive pop-up ads, so be it. But it violates federal law to secretly install software that forces consumers to get pop-ups that disrupt their computer use."