After reading this thread yesterday I got curious about the BK ribs and decided to check them out.  I went to 5 BKs and all were sold out.  These ribs can not be that popular.  All had an oval sticker over the menu board that read “Sold Out”, even one BK that was a little out the way where I was sure they would not be sold out.
 
Being a paranoid conspiracy theorist I have come to the conclusion that this shortage is just a marketing ploy, they even had the preprinted “Sold Out” stickers ready.  Get people curious about the ribs and then flood their store with them.
 
joe