To be fair, it would be very unreasonable for anyone to make the claim that Lolita is erotica.

The Supreme Court define obscenity as being a work that was reasonably lude by the standards of the day, and lacked "serious literary, artistic, political, or scientific value." Lolita doesn't really fit this description due to its literary and artistic value.

I haven't read the blog in question, but obviously issues like this are trickier to decide with contemporary artists that are unestablished. Google certainly doesn't want to be labeled as being a distributor of child pornography, and you can't really compare some guy's blog to a book like Lolita.

Actually erotica is not automatically obscene. Lolita need not be non-erotic, to be non-obscene.