They are used to plan escapes, intimidate witnesses and to transmit sexually-explicit photographs. Illegal cell phones in Ohio's 28 prisons are a growing problem that prison authorities say they're aggressively combating.
It's against prison rules for an inmate to be in possession of a cell phone. In some cases, cases are referred to the State Highway Patrol to investigate, and that information is forwarded to local prosecutors for consideration.
Still, convicts are finding a way to get their hands on what appears to be the contraband of choice behind bars.
"Prison guards is the main reason contraband is in the institution," said Anthony Lemons, who served nearly two decades in Ohio prisons. He's now a free man who was granted a new trial to prove his innocence in a 1995 murder.
"Some corrections officers are just corrupt," Lemons said.
The state confiscated 488 cell phones in state prisons last year or nearly double the number they seized in the year before.
Kenneth Kochevar has been running the Cuyhaoga County Jail for years. He says cell phones poses a huge security risk.
"If an inmate gets a cell phone, he can make an unrecorded call. He can call a witness or a victim of his crime, and he can threaten them, 'Don't show up in court or you're dead,' " Kochevar said.
While cell phones are fast becoming the most popular type of contraband, state records show that weapons and drugs are constantly found in the possession of inmates.
State seizures of alcohol and marijuana totaled 2,113 last year, compared to 1,376 seizures the year before.
The number of weapons confiscated, mostly knives or shanks, were about the same in the past two years -- 1,044 in 2013 and 954 in 2012.
Lemons says having a weapon behind bars is a necessity.
"You need a weapon because it's dog-eat-dog in prison," he said.
In addition to a sharp increase in contraband cell phones, prison officials say they are seeing a rise in suboxone, an addiction treatment drug that some convicts use to get high.
Guards are finding strips of the drug on the back of stamps and even on adhesive tape for packages.
Prison officials say all incoming mail is being carefully inspected.