Okay a simple and humane solution to appease the New Hampshire crowd in this thread. Even if you don't rein from NH, you definitely should register your ride there as your plates might actually transmit your feelings to any of the vermin who exist to yank your cable)
Anyhow, I'll make this short(for liability mostly).
Secondary, low voltage routed to the external casing...
No, it won't kill them but I feel considering the current assumed to be pulsing in the cable, I don't believe they will ever grab another, they don't have to. Just the task of charging their own will become a task monumental hell afyer, as they recall it, they somehow got really damn lucky.
And nobody wire up a model t coil neither. Your midnight backdoor pluggers will do all the heavy lifting to insure your reminder is the gift that keeps giving...
Just make sure you flip it off before plugging in or out..