There isnât really a way to prevent people from âstealingâ your story unless you simply donât share it, ever.
I think it also depends on what your goals are. If youâre just writing for fun and donât plan to ever publish anything, itâs surely unpleasant to have someone else rip off your work, but it might not hurt you as much as if you had plans to actually publish it.
If youâre seriously planning to publish anything, Iâd say only upload first drafts, never the final manuscript, at least not in full.
Also, keep in mind that copyright infringement only really happens to already popular authors as it means that someone uploads their story illegally but doesnât pretend itâs theirs. Like, if you find copies of Harry Potter on here for example. It hurts the author because they lose revenue.
Plagiarism, on the other hand, is when someone takes someone elseâs story and passes it off as their own. This one is much more dangerous and is targeted more at smaller lesser known authors.
So itâs the second instance you want to be wary of.