Freedom of speech allows US citizens to post anything they want, nudity is not allowed because minors are not allowed to watch nude content and the websites have minor members.
The more you react to these stupid fan pages, the more these pages will be created. You will not understand this, because there is difference in our mentalities. Pakistan is a conserved nation today. In the past it used to be a modern nation. India was conserved and traditional 2-3 decades back but is modernizing now. 3 decades back Pakistan was way more modern and civilized than India. Times have truly turned for the worse.
Rather than satisfying extremists by banning these pages, is it not more important to control them, teach them that nothing is above law, eliminate these evil from the society?