Just playing devil's advocate, but how many words would you need to change before that manifesto ceases to be objectionable? Wouldn't it be trivial to 's/word/anotherword/g' to get around the censors?
Most western countries distinguish between free speech and incitement to murder. Relatively uncontroversial.
Also note that the header is clickbait: you get 14 yrs for possession, not for reading.
There's a lot of debate out there on this. Reddit seems to strongly disagree with it.