Airtime has become the new hard currency in South Africa's prisons. The Department of Correctional Services has struggled to deal with the increase in cellphone use by inmates across the country.Several prisoners who spoke to The Times yesterday said they were using airtime for bartering, as cigarettes were used in the past."It all depends on what you need and what you are willing to part with," said an inmate.According to prisoners, airtime can be used to buy groceries or drugs."If you have R29 airtime you can get a packet of cigarettes," another inmate said.Airtime is easier to smuggle into prison than cigarettes because it entails merely asking a family member to buy it and SMS the voucher number to the prisoner. The number is exchanged for whatever the holder wants.The requests are usually for several small amounts instead of one large tranche of airtime. The more airtime you have, the better bargaining position you are in ."Prison is a place where we have a lot of time and nothing to do, so we are on the internet. I've experienced a lot since I've been here. I'm on Twitter, Facebook, Instagram and Whatsapp."Despite cellphones being contraband in prisons, inmates continuously find new ways of bringing the devices in. In December, police and warders at Pretoria's Kgosi MampuruII prison discovered dozens of memory sticks and three phones inside three milk cartons in Czech businessman Radovan Krejcir's cell.Those assisting him took two condoms filled with water and put them in the carton. Wedged tightly between the condoms were the memory sticks and cellphones. The cartons were resealed."There are many ways to get a cellphone into prison. The inmates who go to court and rob other prisoners in holding cells wrap the cellphones in plastic and put them up their [anus]. The inmates come back to the prison and sell them to us," one prisoner said.Another prisoner confirmed the involvement of prison warders and said the department's measures to curb cellphone use would not succeed because of the warders' connivance."They are greedy and corrupt and it is easy to smuggle things into prison if you have money to pay them," said another inmate.Prison authorities have turned to a hi-tech system to curb illegal cellphone use behind bars.The system was installed at the Kgosi Mampuru II but appears not to have been effective.Yesterday, a prisoner at the maximum security prison was able to speak freely on his cellphone from his prison cell."These so-called cellphone detectors are not working. It has been almost a year since they put them here," he said.Research by Just Detention SA has found that many prison fights break out over borrowed cellphones or the refusal of an inmate to repay borrowed airtime."The department is increasingly worried about the access to cellphones in prisons and when there is violence it is usually followed by searches for cellphones," said Just Detention International's Sasha Gear.Cellphone use in prisons came under the spotlight when the man alleged to have murdered Jayde Panayiotou, Sizwezakhe Vumazonke, appeared to have been chatting away on his Facebook profile from the St Albans prison in Eastern Cape.Last year, two of the Waterkloof Four, convicted of murdering a homeless man, had their parole revoked when footage of them allegedly drinking alcohol and using a cellphone at Kgosi Mampuru Prison emerged.Four months ago the department said it was exploring the possibility of using signal jammers to curb cellphone use. It said it was unable to respond to a request for comment yesterday.Clare Ballard, of Lawyers for Human Rights, said signal jammers were controversial and an unnecessary expense."The department needs to use its own systems more carefully. Correctional officials are often the ones who are smuggling the cellphones into the prisons," said Ballard...