Its important that anyone reading fiction knows its fiction.
Without that we can run into a situation where a fictional story on the radio convinces the public that we are under alien attack in what could be called a war of the worlds.
Yes! Or a situation where the public was not under any misconception at all, where there were multiple intermissions throughout the play calling attention to the fact that it was a work of fiction, but someone made up the idea of mass panic because it made for a good story that sold a lot of newspapers!
I would say that it's the responsibility of the reader to read any content in the context of which it's published. For example, to expect a radio play to be fictional as the vast majority of listeners did.
Without that we can run into a situation where a fictional story on the radio convinces the public that we are under alien attack in what could be called a war of the worlds.