SANTA FE, N.M. (AP) — One rural county's ban on the use cellphones and "ballot selfies" at voting locations in New Mexico is prompting a backlash from advocates for civil liberties. The American Civil Liberties Union sent a letter of advice Thursday to county clerks that run elections across the state. It urges them to lift or avoid restrictions on cellphone use and to allow voters to take photos of themselves casting ballots. Rio Arriba County posts signs that say no cell phone usage during voting at all polling places and has for more than a decade. Elections Bureau Chief Michele Jordan says that ensures the privacy of voters. New Mexico law does not address the "ballot selfie" issue explicitly. It says voters shall not show the contents of their completed ballots.