ATLANTA (AP) — Inmates at some Georgia prisons have been using cellphones to traffic drugs, smuggle in contraband, steal identities and, in at least one case, to arrange a violent attack on an inmate suspected of snitching, according to federal indictments unsealed Thursday that target a dozen people who officials say were involved in two prison-based crime rings.

The inmates used prison employees to smuggle cellphones and other contraband into the prisons, two indictments say. They then used the phones to communicate with networks of other inmates, friends on the outside and prison staff members.

"The one commonality that runs through it all is the ready access to and use of cellphones and smartphones by the inmates that allowed them to continue their victimization of citizens and the community even while they were behind bars," U.S. Attorney John Horn said. The investigation is ongoing, he said.

In the fiscal year that ended June 30, more than 7,000 cellphones were confiscated at Georgia prisons, either from inmates or from people trying to smuggle them in, Georgia Department of Corrections Commissioner Homer Bryson said. Since July 1, more than a thousand have been seized.

Since Bryson became commissioner in February, 50 people, including 22 corrections staff members, have been arrested trying to bring contraband into prisons, he said.

"Contraband is not a new problem within prison systems within this country, but what is new is what technology has enabled that contraband to do, and it is a huge issue," Bryson added.

The indictments name four inmates, three paroled inmates, one former prison guard, one former contract worker and three civilians. Those who weren't already in prison have been arrested, Horn said.

It was not immediately clear whether any of those indicted has a lawyer who could comment on the charges.

This case came to light when law enforcement in Cobb and Gwinnett counties got reports of fraud from citizens and the activity was traced to state prisons, said Special Agent Britt Johnson, who heads the FBI's Atlanta field office.

One indictment accuses Donald Howard Hinley of running a drug trafficking ring from inside Valdosta State Prison, routinely brokering significant drug deals in the Atlanta area and elsewhere in Georgia.

On one occasion, prison officer Anekra Artina Williams smuggled in prescription pain medication and methamphetamine into the prison in exchange for $500, the indictment says. According to phone calls and text messages, Hinley arranged for liquor to be smuggled in in large plastic water bottles and had his associates package marijuana and methamphetamine so Williams could hide it under her vest, prosecutors say.

Hinley instructed an associate at Telfair State Prison to kill another inmate he believed would likely testify against Hinley's girlfriend in a drug trafficking case, the indictment says. Hinley also told his associate to shoot the potential witness' family members once the associate was released, saying "... pop them all off, kids, grandmamas, daddies, I don't give a (expletive), right?" and bragged to his girlfriend by phone, describing his associate as "a straight (expletive) killing machine."

The second indictment says Mims Morris, Johnathan Silvers and Adam Smith, members of the Ghostface gang, used phones to traffic drugs while at Phillips State Prison in Buford, and that Morris also used cellphones to commit identity theft. The indictment says Morris and Silvers even had phones and other contraband while they were in administrative segregation, known as "the hole."

In wiretapped cellphone conversations, Silvers bragged that his cellmate was watching a movie on his phone while they were in the hole and talked about posting on Facebook and buying shoes online. He said all the guards knew he had a cellphone, the indictment says.

Silvers paid prison kitchen worker Charonda Edwards to smuggle in contraband, and she also provided valuable information, like when the prison would be on lockdown, the indictment says. They relied on prison orderlies and other inmates to move drugs, cellphones and other items they sold to other inmates.

Using a cellphone, Morris posed as a fraud specialist for a credit card company and tricked a woman into revealing her personal information, which he used to authorize a transfer of $2,200 to a card he controlled and to apply for additional cards.

Morris also instructed a friend who wasn't in prison to post ads on Craigslist looking to hire people for construction and roofing jobs and providing his prison cellphone in the ad, the indictment says. He planned to get the job applicants' personal information and open debit cards in their names, prosecutors allege.