The server that hosts MR and most eBooks is located in Canada. There is also a server in the USA to host eBooks. Canada has a life+50 copyright. The USA has a life+70 copyright.
What that means is once the author dies, the books retain copyright for another 50 or 70 years. Some eBooks are public domain only in like+50 countries such as Canada but not in life+70 such as the USA. Some eBooks where published in the USA and no longer have a copyright and are only copyright in the USA. Those that are only public domain in the USA are hosted on a server in the USA.
So 1984 can be hosted in Canada because it is in the public domain there. But in the USA, it is not in the public domain yet.
We can thank Disney for screwing with copyright.