I have worked for many years in a neighboring 911 center and would like to offer my two cents on the subject...
Any time a person calls in a suspicious box, package, etc. a "better safe than sorry" attitude has to be taken for both liability and public safety reasons. No amount of questioning or complaining is going to change law enforcement response to this. Unfortunately, this is the world we now live in. A better solution would be to avoid causing the initial alarm/phone call to us. Although ammo boxes tend to keep caches warm and dry and the animals away, they do cause alarm. And, let me just add, people tend to be alarmed by quite a lot of things these days. My suggestion would be to limit cache containers to clear tupperware or lock-n-lock containers that clearly show the contents inside. Also, when placing caches, really, REALLY try to think about how something may be perceived as being suspicious. Does that micro really need to be placed outside a courthouse or public building where security is an issue? Bridges are routinely checked now not only for security reasons but for structural integrity and your cache may be found. And yes, there are costs involved with calling in bomb squads, shutting down roadways etc. It is not as simple as it sounds. This situation is going to come up again unless we make some changes. The police/Homeland Security type reponse, even when they are aware that a cache is in the area, will not change.