Six leading advertising associations and civil rights watchdog groups have applied to file an amicus brief in a lawsuit challenging Utah's "Do Not E-mail" registry and say in their application that the case is important "to all parties with a vested interest in free and unfettered availability of email as a communications channel," MediaPost reports. The lawsuit was filed in November by The Free Speech Coalition, an adult-entertainment trade organization that wants Utah's Child Protection Registry Act invalidated.

The law prohibits email marketers from sending various types of promotions - including those related to pornography, alcohol, cigarettes or gambling - to any email address on a registry of email addresses submitted by parents of children under 18. Defenders of the law say it will protect children.

The six organization - the American Advertising Federation, American Association of Advertising Agencies, Association of National Advertisers, Inc., Email Service Provider Coalition, Electronic Frontier Foundation, and Center for Democracy & Technology - argue, as do those filing suit, that it impedes interstate commerce, violates free speech laws and is too vague about the types of banned emails.

They also say that if registry information were somehow exposed, it could be used to target children.