Whether is Lemmy, federated, corporate owned, or even your own private site - nothing you put on the internet is ever truly private. If you have a public profile someone can access it and copy it.
The only things I'll say that I have an expectation of privacy is health related, everything else I fully expect someone else to read, copy, and multiply.
I think there should be, but I never expect there to be. Did people's parents not teach them about putting things on the internet they didn't want shared?