"DNS Blacklist: Since 2007, the Swiss federal police has
established several partnerships with ISP, which are based on
a voluntary collaboration. These measures have been the result
of a strong collaboration between national NGOs like ECPAT
Switzerland or the Swiss Agency for Criminal Prevention and
the CYCO. 106 The majority of ISPs (14, which represent 85%
of all Swiss users) have subscribed to a contract with the
government. 107 This implies that the CYCO will manage a list
of child pornographic websites that have to be blocked by the
providers on the Swiss territory. 108 These partnerships are based
on a trust relationship, which means that ISPs usually do not
review the sites before blocking. The system is successful in spite
of the fact that there is no compulsory reporting system for ISPs
to refer child pornography websites found on their system. The
national law allows the service to block any kind of representation
depicting sexual acts involving children, including photography,
films as well as pictures, virtual or animated images (hentai). "

http://www.ecpat.org/wp-content/uploads/legacy/ecpat_journal_apr2012_final.pdf