A method or system of providing security utilizing RFID tagged items exiting or entering a retail establishment. A RFID tag value of a RFID tagged item being checked out is: read by a first RFID reader, added to an exit queue, and read by a second RFID reader at an exit of the retail establishment after which it is ascertained that the RFID tag value is or is not in the exit queue respectively resulting in deletion of the RFID tag value from the exit queue or raising a security alert. A RFID tag value of a first RFID tagged item at an entrance of the retail establishment is read by a RFID reader, added to an entrance queue, determined as having come from the retail establishment, and ascertained to have entered the retail establishment to be returned for a refund or exchanged for a second RFID tagged item.