Amy (left) and Ashley Stabe

When Amy Muston married Ashley Stabe married last year, the couple took Stabe's name.

But in 2006, South Dakota voters passed a constitutional amendment that banned and denied recognition of same-sex marriage and civil unions.

And since state law requires drivers to provide legal documentation of a name change when applying for a license, the state is refusing to accept their Iowa marriage license as a legal basis for the name change, reports the Souix Falls Argus Leader.

The couple has now filed petitions in the Minnehaha and Union County courts to change their names. Both petitions have the backing of the American Civil Liberties Union of South Dakota.

The ACLU sees the license denials as evidence that such laws turn homosexuals into second-class citizens and threaten to drive people from the state. If the courts refuse to accept the name-change petition on the grounds that doing so would endorse a same-sex union, lawsuits might follow.

"This is an emerging issue for states that have passed these constitutional amendments prohibiting same-sex marriage," said Robert Doody, executive director of the South Dakota ACLU. "They're being used to deny people really basic rights."

According to the Department of Public Safety, which issues the driver's licenses, a message in bold print on the application indicates that the state will not accept any documents related to same-sex marriage.