But, actually, probably should go into "legality". No, there are no specific laws* against fictional depictions or writings of pedophilic acts (though there are laws against the acts themselves, as well as possessing recordings of those acts). However, we still have a lot of obscenity laws, and, yeah, I think you could argue that "cub porn" or "shota/loli" or whatever is obscene (fuck, kind of the point, really), but those obscenity laws are actually really, really toothless in America, due to our courts mostly siding with the "let's not do a censorship" side, and the fact what is considered "obscene" in a culture changes over time. Now, you can argue maybe the laws should more specifically define "obscenity", but the truth is the vagueness is a feature, not a bug, allowing courts to change with the cultural norms.
Mostly, America has allowed entertainment industries to police themselves, so you get rating systems in games and movies and, actually, we mostly just trust the printing industry to know what they're doing, I guess. Basically, that's what e621 is doing (or their financial backers are forcing them to do). In America, our government doesn't actually do much censoring. They don't need to. They let us do it ourselves (usually in the form of big corporate entities, which may be worse!).
There have been an occasional case where, yes, someone is taken to trial for obscenity with something like what we're discussing here, and on least one occasion in my memory a "loli" artist plead guilty, but in that case she was poor as dirt and couldn't afford to go to trial so it was actually cheaper for her to just pay the fucking fine (which is fucked up, but, that's how it works sometimes) (and this was a while back and I may be misremembering and I sure as hell can't source that, sorry).
*Like dronon, caveat that this is USA, and not a lawyer so add a silent "as far as I know".
But, actually, probably should go into "legality". No, there are no specific laws* against fictional depictions or writings of pedophilic acts (though there are laws against the acts themselves, as well as possessing recordings of those acts). However, we still have a lot of obscenity laws, and, yeah, I think you could argue that "cub porn" or "shota/loli" or whatever is obscene (fuck, kind of the point, really), but those obscenity laws are actually really, really toothless in America, due to our courts mostly siding with the "let's not do a censorship" side, and the fact what is considered "obscene" in a culture changes over time. Now, you can argue maybe the laws should more specifically define "obscenity", but the truth is the vagueness is a feature, not a bug, allowing courts to change with the cultural norms.
Mostly, America has allowed entertainment industries to police themselves, so you get rating systems in games and movies and, actually, we mostly just trust the printing industry to know what they're doing, I guess. Basically, that's what e621 is doing (or their financial backers are forcing them to do). In America, our government doesn't actually do much censoring. They don't need to. They let us do it ourselves (usually in the form of big corporate entities, which may be worse!).
There have been an occasional case where, yes, someone is taken to trial for obscenity with something like what we're discussing here, and on least one occasion in my memory a "loli" artist plead guilty, but in that case she was poor as dirt and couldn't afford to go to trial so it was actually cheaper for her to just pay the fucking fine (which is fucked up, but, that's how it works sometimes) (and this was a while back and I may be misremembering and I sure as hell can't source that, sorry).
*Like dronon, caveat that this is USA, and not a lawyer so add a silent "as far as I know".