Makes sense. Their calls are recorded but not always monitored, using AI to detect certain key words to flag for manual review just makes sense. No surprise that they're also training on that data, since they have it.
It's also not just the phone calls. COVID got many facilities into video visitation, or telephone visitation using cheap (think Amazon Fire but worse) tablets, both of which go through a service which records them. The phones have to be tapped to do that as phones are not, by nature, recorded. You have to add the hardware to do that. But over a tablet or computer? The recording is built right in.
It gets worse. A lot of those tablets have games on them. Microsoft proved almost 20 years ago that they could make money by selling gamers' habits and play styles — it's the corporate side of the reason Achievements exist. In short, so they can tell publishers how you play games. What objectives you go for. What you do first and what you save for later (note how they're all time and date stamped). Imagine if we gave inmates a game like A Way Out (the co-op game where two players break out of a prison), but make it way more open ended. The state would sign on because they could see what kinds of stuff the inmates come up with and focus on security in those areas. Pretty obvious. But you could also use it to determine other aspects of human behaviour.
It's a data mine and they can't opt out, except by not using it. "But they'll just read books like they did before computers." Watch them start to take books away, donate them to libraries and other community outlets, and put the books on the tablets. So they can still read, they just have to do it on the tablet, which also has the games and other stuff.
What a boring dystopia.
Oh, and if you think "but I'm not an inmate," look at your phone. And look how people treat others who don't use the same brand. Think about it.