Science fiction is any idea that occurs in the head and doesn't exist yet but soon will and will change everything for everybody and nothing will ever be the same again. As soon as you have an idea that changes some small part of the world you are writing science fiction. It is always the art of the possible never the impossible.
When any government or any church for that matter undertakes to say to its subjects This you may not read this you must not see this you are forbidden to know the end result is tyranny and oppression no matter how holy the motives.