When they were babies both of my kids happily chewed on lightning cables that were plugged into a charger. They're both still here but all of those cables stopped working shortly thereafter.

"When a Lightning cable is just lying somewhere connected to a charger/computer, but not connected to a device, HiFive limits current on the PWR to a really small value (around 10-15 mA according to my measurements). To enable full current, 0x74 request must be issued by Tristar and processed by HiFive."

https://nyansatan.github.io/lightning/

Woke up with a lightning connector burning into my back, was very uncomfortable