There is a book that is 200 pages long. If you read the entire book, you will 100% get a neurodegenerative disease and die in 1-5 years. Everybody knows this. There are studies. Every reputable organization, even very pro-free-speech ones, are like "no this specific book WILL literally kill you."
There are no consequences to reading the first page of the book. There are studies. The only risk is that you might be interested enough that you'd like to read the rest (especially if you didn't know about the effect.)
(More details: The effects of reading past Page 1 are hotly debated - you do need to read all 200 pages to get the disease, but some kind of compulsion kicks in over time and makes you much more inclined to finish the book. Reading to page 10 is a little dangerous, reading to page 50 or past is very dangerous, but it's kind of unclear how much. The compulsion is NOT measurably present from the first page.)
Every government has banned this book, but it's pretty easy to find copies online or (with a bit more work) in person. By all accounts, the writing is quite beautiful. It is even easier to find copies of the first page, since everyone agrees it's not dangerous.
(this is curiosity / idle research for a fiction project)