The Florida Department of Corrections is one of the many state prison systems that rely on private contractors to supply electronic messaging and access to electronic music files and books for prisoners. For seven years, Florida ’ s prisoners have bought music through Access Corrections, a company that took in $11.3 million selling songs at $1.70 each — nearly twice what the typical song costs on the marketplaces available to people who aren ’ t incarcerated. This is hardly exceptional:...