In Cook County jails, prisoners are charged as much as $15 a call to be in touch with their relatives. The exploitive rates can force families — already struggling with the burdens of having a loved one locked up — to choose between supporting their loved one or paying for heat or food. An Illinois study found that the price of phone calls from prison was one of the two most significant barriers to family contact during incarceration. Why are the most captive and vulnerable being charged such brutal rates for a phone call? Because they can be. They have …