We have them on our apartment buildings. IMHO they have saved us a ton of time and money by not having to replace locks and doors after an emergency situation.  I do know a record is kept every time the FD to access the box.  I believe a radio signal is sent to dispatch to the responding unit, releasing the access key for use.  Seems like a fairly secure system.
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Our most important survival tool is our brain, and for many, that tool is way underused! SBRaider
Head Cat Herder