dlloyd:
Why not use an appropriate sized thermistor? Kind of like an electronic clutch for current.
http://www.ohioelectricmotors.com/what-are-thermistors-and-how-do-they-limit-inrush-current-702
I'm not sure how to select one, and I'm not sure if it would limit the current quickly enough in a stall condition to protect someone's hand if it gets in the way of the moving parts. It is only a tiny DC motor, but with a 30:1 gear reduction, so there's probably not much danger, but the whole point is to stop the thing immediately if something gets in the way.
I did search Digikey though. If any of them are suitable, it would be one of these through hole ones which are in stock:
I'm gonna check out the datasheets of a few and see if I can suss out how quickly they'd react, but I doubt it will be fast enough.