All objects whose mere possession or trafficking is illegal (such as stolen objects, drugs, pornographic materials or in any way degrading to human beings, etc.). Objects whose possession requires a license, without such license or authorization (such as weapons and/or ammunition). Any type of material that is polluting or dangerous (such as flammable objects or dangerous substances). No food may be inserted in the lockers, unless it is packaged food that cannot spill, stain the lockers or produce odors of any kind.