It used to have maple syrup, so it had a pretty small opening which made it hard to get the pennies out later.
The house was robbed while my parents were out and you could see the ring in the carpet where the thieves had moved the jar to try to take it then thought better of it. They also decided not to take the stereo, but it had been pulled away from the wall. but it may have been too complex to disconnect, grab all the wires, then carry out all the components. They didn't get the cloth envelope with cash that my parents had placed in the freezer until they got around to depositing it (cold cash) or the pistol that my father had somewhere in the house.