It’s the belief online that [...]

Well, the idea of the "Law of Attraction" is far older than the internet; I recall reading about it in a book on old timey "magick" teachings many years ago. If I recall correctly, the idea was that the only real "magick" in this world is our attention/willpower. So the things we're attracted to, or the things that we use our willpower toward or spend our time on, are the things we are "magicking" into existence, so to speak.

So if one uses their willpower toward helping others and being a positive person, that's using the law of attraction to the benefit of others and yourself.

If one uses their willpower to be a total jerk and only look out for themselves, that's using the law of attraction purely for your own benefit, and maybe to the detriment of others.

One could also use their willpower to, say, stop smoking cigarettes. That would be using the law of attraction for self improvement.

That was my understanding of the idea, anyway. Haven't read about it since then. I liked the book because it was very clear from the beginning that "magick" is no shortcut to real results because "magick" is just human willpower manifested through actions, and anyone who was offering quick solutions via "magick" was a scam artist.