One of the details that I'm not seeing in the article is does this apply to State prison, Federal prison, or both? Based on my experience in Federal prison I expect that it's more targeted at State prison since I often talked to other inmates that were vocal about the atrocious rates they experienced while in those systems.

In Federal prison the phone and e-mail system is still pretty bad, but not as bad. We often joked that it was like going into a time machine nearly 25 years in the past where "phone minutes" were still a thing and they even invented the idea of "email minutes".

On the note of "email minutes" they actually charge you for the entire time you are in the system which includes wrestling with their UI/UX which has obviously been "fine tuned" to be as abusive as possible to drain your email minutes. They also remove basic features like copy/paste and in general most of the basic typing features you take for granted every day like holding CTRL or SHIFT to navigate between words or type over existing words. This is again another cheap tactic to ensure that generating text output is as slow as possible. There are similar tricks that are used to slow the progress of reading messages. (FWIW printing messages is somewhat possible and costs about $0.70 per message since you can't combine them into multiple on the same page and the font size during printing is large)

Entertainingly this creates a class of inmates that are highly adept at navigating this stupid system and can churn out messages faster than anyone else combined with decent typing skills and knowledge of all the failures of the system. It's not a bad "hustle" as it's actually pretty impactful to help people send messages to their loved ones.

Fun story! While I was doing my time I setup a script that uses puppeteer to scrape the front page of HN itself and tried to get the most interesting stories per week. It would then generate a PDF and email it to my friends who would print it out and send it to me, so I actually had a weekly digest of HN in my inmate mail. Originally I didn't know how absurd the rules would be about keywords and such (spoiler, they're not very strict and mostly only concerned with overt things) so I had a mapping of words that would get modified like the word "Hacker" became "Wacker" and "Auth[entication]" became "Lock" as a way to avoid spooky headlines like "Hacker Steals Authentication Codes" would become "Wacker Steals Lockentication Codes" - it was crude and ended up not being neccessary so a friend of mine modified the script to remove it upon request. I had originally wanted to hook the whole thing up to a printing API to automate the process (the entire thing was thrown together a week before I had to surrender) but the various printing APIs weren't really capable of handling the rules for inmate mail about page limits, colors, labeling, etc.

Ask me anything!