More than a dozen states have laws on their books banning or limiting the so-called robo-calls, Stateline.org reported Friday.

In Oregon, for instance, a new state law bans automated calls to households on the National Do Not Call Registry.

In Indiana, all robo-calls are banned. But in February, a judge dismissed a case attempting to enforce the law, ruling the law shouldn't include political calls because the callers aren't selling "tangible objects," as the law prescribes.

In North Carolina, state Attorney General Roy Cooper is backing legislation that would ban robo-calls to houses on the National Do Not Call Registry, Stateline reported.

"People in North Carolina who have signed up for the Do Not Call Registry have said loud and clear that they don't want to be bothered with telephone solicitations," Cooper said in a letter to the state's political parties that asked candidates to voluntarily comply with the do-not-call list.

Efforts to limit robo-calls have recently failed in Colorado, Ohio, Illinois, and South Carolina.