I'm sure you have nothing to worry about. The batteries will most likely be securely stored underground, not be visible to everyone. I'm sure they'll have at least 1 person at the station or at least security cameras.
It's not like you can just steal these batteries and sell them on the black market. Considering how much they weigh, it's probably near impossible to replace/install a new battery yourself.
I'm not worried about it at all - just that, from what I have seen, there must be some black market for industrial sized batteries (maybe for their metal component?). Whether this impacts on Tesla or not I have no idea - I suspect not.
It's not like you can just steal these batteries and sell them on the black market. Considering how much they weigh, it's probably near impossible to replace/install a new battery yourself.