(he, in this case, would not be the llm but the people over it)
I find those kind of limitation very dystopian and way more dangerous than the threat they claim to fight against.
But it's a rather annoying service if the customer can't predict in advance what sort of tasks they're willing to take on. You should have some idea about what they're normally willing to do for you.
Whether the book takes the form of an llm or an online website or a printed book is merely implementation details.
"No knowledge in Kamar-Taj is forbidden. Only certain practices."
You reminded me of that quote from the Doctor Strange movie.
Even the most "dangerous" knowledge can be life-saving, depending on the circumstances. When I was a teenager, I read the Terrorist's Handbook, which was a text file circulating on bulletin boards. After 9/11 it vanished, because posession was considered a crime in some jurisdictions.
Knowing how to build a bomb is useless and/or dangerous in civilian life. Ask a Ukrainian if it is useful knowledge!
Knowing all about nuclear weapons doesn't mean you're going to blow up a city. But if someone else does, then you'll have the knowledge needed to avoid the worst of the radiation and maybe survive.
It'll be dystopian when that'll become your only source of information, and we're working on getting there. If you want to be horrified, look at what students (in school and post-secondary) are doing these days.
It's insane to offload your thinking and knowledge to a machine owned by other people, but you have to if you want to keep up with the rat race.