MOST of the roughly 2.2m incarcerated Americans will eventually be freed. Those who remain in contact with loved ones on the outside are less likely, studies show, to return to a life of crime after serving their time. Much as voters hate criminals, they also have an interest in not being mugged. So why do prisons make it so hard for inmates to phone their families?

Prisoners’ families tend to be poor. Talking to a brother, son or father behind bars can incur an upfront fee as high as $4.99; per-minute charges may reach $0.89. Americans at liberty, even if they don’t have Skype, can easily get unlimited domestic calls for $9.99 a month. That would buy one six-minute call from a state prison in Georgia to a neighbouring state.

Outside prison, phone companies compete fiercely for customers. Inside, they don’t have to. Each state typically grants a single company a monopoly over telephones in any given prison. The result is high prices and a booming trade among inmates in contraband mobile phones.

To be fair, phones in prisons require special security features, such as the ability to record, monitor and block calls. Global Tel*Link, one of America’s biggest providers of phone services in prisons, insists that these “sophisticated security elements [often require] numerous on-site personnel, instruction and training”, which make them far costlier to install and maintain than traditional telephones.

But some see a darker reason for the high costs. In all but a few states the phone-service providers return a large share (sometimes more than half) of revenue collected from each phone to the facility in “commissions”. These commissions provide a ready source of discretionary money for cash-strapped prison systems to cope with a rising inmate population. But they do so by taking money from those whom Foster Campbell, one of Louisiana’s five public-service commissioners, calls “the least of these…poor people in bad situations [with] no voice…and no political clout.” No politician wants to be seen as soft on criminals, but exorbitant charges also hurt the 2.7m children who have a parent behind bars. Many of those parents are imprisoned in different states, far from home.

Mr Campbell thinks service providers are simply greedy. But Eleanor Holmes Norton, a congresswoman from Washington, DC, and the chair of the Congressional Black Caucus’s Prison Telecom Reform Working Group, blames loose regulation, which has allowed companies to “extort excessive telephone rates from the people in society least able to pay them”.

That may soon change. More than a decade after a federal court ruled that the Federal Communications Commission (FCC) may regulate prison phone calls, including “the reasonableness of rates”, the agency has taken notice. Late last year it released a “notice of proposed rule-making”. It is now reviewing public comments. Mignon Clyburn, who became the FCC’s acting chairwoman on May 20th, believes that charges should be “just and reasonable”. A small reform, perhaps, but lower rates might help prisoners go straight.