Neil Gaiman’s long and passionate answer to a question posed to him from a reader about why he is defending lolicon (Wiki def. here) and why he is appalled by the arrest of a comic collector for owning manga comics which allegedly depict minors engaged in sexual acts.
In this case you obviously have read lolicon, and I haven’t. I don’t know whether you’re writing from personal experience here, and whether you have personally been incited to rape children or give inappropriate hugs by reading it. (I assume you haven’t. I assume that Chris Handley, with his huge manga collection, wasn’t either. I’ve read books that claimed that exposure to porn causes rape, but have seen no statistical evidence that porn causes rape — and indeed have seen claims that the declining number of US rapes may be due to the wider availability of porn. Honestly, I think it’s a red herring in First Amendment matters, and I’ll leave it for other people to argue about.) Still, you seem to want lolicon banned, and people prosecuted for owning it, and I don’t. You ask, What makes it worth defending? and the only answer I can give is this: Freedom to write, freedom to read, freedom to own material that you believe is worth defending means you’re going to have to stand up for stuff you don’t believe is worth defending, even stuff you find actively distasteful, because laws are big blunt instruments that do not differentiate between what you like and what you don’t, because prosecutors are humans and bear grudges and fight for re-election, because one person’s obscenity is another person’s art.
Because if you don’t stand up for the stuff you don’t like, when they come for the stuff you do like, you’ve already lost.
Some background on the Christopher Handley case can be found here.