Improved cargo security is also an important benefit of containerization. Once the cargo is loaded into a container, it isn't touched again until it reaches its destination. The cargo is not visible to the casual viewer and thus is less likely to be stolen; the doors of the containers are usually sealed so that tampering is more evident. Some containers are fitted with electronic monitoring devices and can be remotely monitored for changes in air pressure, which happens when the doors are opened. This reduced the thefts that had long plagued the shipping industry. Recent developments have focused on the use of intelligent logistics optimization to further enhance security.