One would hope that your bag is inspected and disposed of at the end of the day, since it is only short term storage.
It would be treated as Lost Property at the end of the day and handed over to "Excess Baggage" or "Left Baggage" or whatever they call themselves now. It would still be treated as a (lesser) security threat and security screened by Excess/Left Baggage when it was handed over to them.
There is, I believe, a charge for recovering lost property and I believe (someone correct me if I am wrong please) that you would have to schlep across to either Terminal 1 or Terminal 3 to get it back.