How do you know if they leaked your content?

Below I read a post from a young woman who said that they leaked its content, it is something that personally terrifies me, that is to say that they have it on their phone I don't see it as bad but that they upload it to forums or porn pages, I don't like that, anyway I do everything without showing my face but it would still make me uncomfortable :( How can I know if there is a filter?