If the bigbox stores are anchor tenants at a mall; the mall common area maybe prohibited, but the store may not be. Example, Battlefield Mall in Springfield prohibits CC in the general areas, posted at all the entrances for the common areas; however, none of the bigbox stores entrances are posted. So, in the store, you may be ok, but out in the common areas, it could be prohibited.
There is a web site with some places listed as non-participators to the 2A...for the life of me I can't recall this site. I have it bookmarked on my home computer, but not at work. Sorry!