Cargo left uninspected in airplanes

According to N.Y. Senator Charles Schumer, there are still holes in the security at airports. The federal Transportation Security Administration plans to enforce more strict background checks on both cargo and employees checking the cargo. Schumer states that 100% of cargo on planes remains unchecked because the costs are too high to check it. There is a "known shipper" system set up, but unknown cargo is shipped with these packages. Schumer has asked the president to better enforces these practices and improve TSA practices.