http://gothamist.com/2011/10/08/zuccotti_park_owners_may_not_be_abl.php
Summary: Zucotti Park, while privately owned, is zoned for 24 public access, which might make it impossible for the private owners to clear it (now that Bloomberg has said they won't do it). And with that in mind, the article lists a bunch of similar properties very nearby with the same zoning that are inside and offer bathroom and other facilities.
Michael