How to protect against fakes?
Basically do your own research.
If some tell that Elon Musk buys Ethereum, see on his public statements about it. Search on twitter (but make sure you didn't find fake accunts with that name), search on blogs, search on reputable news agencies.
If somebody tells that certain bank or institution plans certain service, check that bank's pages, social media or even ask their support.
..Something like this.
Especially if you want to invest based on certain news, you have spend some time and effort to make sure everything is all right.
I agree. It is very important that we do our own research and not believe in anything we see or read on the internet right away. However, these days it is getting a bit harder and harder to determine authentic news from the fake ones. That said, a little self research do not hurt and often works.