Who decides what is banned by these rules. Is a rape in a non-#*$! film OK, for example?
It also only applies to ISPs who agree to cooperate with the government scheme.
It also means more powers given to the government to monitor what we do online. Bear in mind the British government already stores and examines all UK internet traffic and almost all transatlantic traffic.
Worst of all, automatic filters will block a lot of legal material.