Back channel power safety

I noticed when moving my steppers around the boards leds lit up for a second, I assume power was back channeled into the board via the motors acting as a generator. Is this dangerous for the unit or something I dont need to worry about? I assume it COULD be bad for it and I should move the motors slowly when positioning them.

Slow down or you can pop something.

Ben mentions this at 3:44.

I wish they had some diode protection because this makes me very paranoid lol.

The ultimachine boards do.