Columbus Day Sale
A small window of opportunity you can walk into a store and take at your own risk what you want without paying ; e.g. after a natural disaster or social unrest or war. The sale does not have to occur on any specific day, but it requires certain conditions. It is illegal in almost all circumstances, with the exception of some areas which have been devastated by a disaster and for which taking certain items is necessary for basic survival.
On a Columbus Day Sale, the real cost maybe your life.