I think there might be some jurisdictional issues at play here. I don't know about New Zealand, but in Australia a lot of material that is available for sale in the US is banned.
For example, via our Office of Film and Literature Classification laws, import regs ban the importation of anything (including drawings, 'toons etc) that appears to depict a person under the age of 18 in a sexual act.
no subject
For example, via our Office of Film and Literature Classification laws, import regs ban the importation of anything (including drawings, 'toons etc) that appears to depict a person under the age of 18 in a sexual act.