IIRC, calls to and from inmates are recorded and analyzed. It costs more for the storage, retention and processing of this data, than the mere connection and data transfer.
> The primary factors driving the FCC’s lower rate caps is the exclusion of security and surveillance costs as well as the exclusion of commissions. [...] With today’s new rules, prison telecoms will be barred from recovering the cost of the majority of such services from ratepayers.
