I haven't heard too much about this yet, but I understand that the event or recognition, etc., is held every year during the last week of September, so since that happens to be now, I thought it might be worth mentioning.
Here are a few links I found about "Banned Books Week" that might help explain it better, or tell a little more about it:
http://en.wikipedia.org/wiki/Banned_Books_Week
http://www.ala.org/ala/aboutala/offices ... ksweek.cfm
http://www.ala.org/ala/aboutala/offices ... ground.cfm