To ban or not to ban websites in schools?

The American Association of School Libraries (AASL) designated September 28th  “Banned Websistes Awareness Day” generating a lot of  praise and heat all at once.  AASL aims at bringing awareness to a number of different banning mentalities that can be identified in schools today. The two most discussed categories of commonly banned websites are gay&lesbian and social media sites (not to mention every single site that contains the word sex).  Throwing the baby with the water is obviously what we are experiencing in schools toady but the issue is far too complex to be addressed with an awareness day. I hope the awareness day will at least set the discussion going. What should or should not be banned in schools and who will decide? What are your thoughts?  On what basis do we decide whether  to block Facebook and other social media sites altogether? Isn’t it unwanted censorship to block sites that portray gay & lesbian rights, or maybe not?  Not sure what the right answer might be and we, surely, have a long road ahead before our thinking starts maturing on this issue. But then, again, could it be,  that we are putting a little too much energy in identifying what to ban and much less in finding what’s good to promote?