In the old days, some snake oil salesman had to travel town to town, speak to a few dozen people at a time to spread his nonsense.
Later, he could self publish books to reach a wider audience.
Today, one can spread stupidity all over the world with just a click of a mouse.
Nibiru first surfaced in a bad fiction story. Key word here is fiction! None of the people who push this Nibiru idiocy tell us where exactly it is. They claim that the Government knows but hides the truth for some nefarious reason.
If Nibiru did exist, and was going to hit us in a little over a year, it would be visible with a naked eye. Every night, tens of thousand of professional and armature astronomers point their telescopes skyward. On almost daily basis they keep finding asteroids and comets, objects much, much smaller and fainter than a planet, but no one had seen Nibiru. And there is only one reason for that: IT DOESN'T EXIST!