They may be referring to a bit more than that. Most inmate supplies, from clothing to blankets to mattresses to hygiene supplies, comes from one company called Bob Barker - no affiliation with the TV personality. There are just a few companies that supply canteen/commissary services. Construction is done by just a few companies.

Things like that may be what they are referring to.

Yeah, fully privatized prisons are just the apotheosis of a broader issue.

While private prisons account for a relatively small percentage of total prisons in America, they're a multi-billion dollar industry, and they lobby for laws that affect all prison populations. So, in that sense, we do have a highly privatized prison system.

And it is highly privatized in the sense that the amount of privatization in that sector should probably be zero. When incarceration is a burden rather than a business, incentives exist to prevent crime and reduce recidivism. Otherwise, there are incentives to invent crimes that did not previously exist and turn ex-convicts into "repeat customers".