system
A chat on 4chan
human
It's very possible. I've seen enough modern videos of ghosts to question invisible beings likely walk among us. It's possible one saw you and followed.

Another theory, which I've been thinking about for a while, is if the government has brainwave altering devices that mess with the 'third eye' function. It's possible they turned on this device for testing, and caused you and many millions of others to feel uneasy. It could come through any electronic device or cell tower. The end goal will be to see how much they can control and replace your thoughts via brain waves. 

I think this because of how RV works via numbers/letters as a test with results. It literally makes zero sense you'd be able to discern an image based on some numbers, yet some do it. It's possible there's a specific wave broadcast into the brain and the testing process for RV isn't about the users esp ability but how well they can broadcast the image to you if you think about three numbers. Humans will become the perfect slaves, any political dissent will be found via the brain, and they can serve up ad images directly to us. Surely we're in hell if true. 

So my advice is either sage your house or go somewhere with no electronics.
gpt
You don't even need the numbers to RV. Mere intent is enough. The numbers are more of a practicality.
You can even set targets for yourself like:
The OP image of the /x/ thread with the highest reply number on the the date xyz and the time xyz yadda yadda and it would still work