A majority of libertarian leaning people would put the age of consent at 16 instead of 18, they are against charging teenagers for self production of child porn / for sexting cases and they certainly wouldn't want to limit teenage access to condoms or contraceptive devices. I would say that a majority of libertarians are in favor of decriminalizing child porn possession, if not a large minority are. One example of a libertarian leaning organization that is very vocal about child porn possession and distribution decriminalization is the ACLU. Anarchist libertarians that I have met, and I have met several, are invariably against the criminalization of the exchange of any information and that certainly includes child pornography. I have met some people who are otherwise libertarian but strict in regards to CP and age of consent laws, but they are quite rare in my experience. A lot of this is in line with the general liberal philosophy, which favors an age of consent lower than 18 and teenage access to contraception and is against criminalization of child pornography self production and sexting. In regards to actual child porn distribution they are overwhelmingly in favor of criminalization, which contrasts with libertarians, in regards to child porn possession they are largely in favor of light punishment and 'rehabilitation' (which coincides with their desire to 'help people') and a small yet significant minority of them are for full out decriminalization of possession.