It's not always the first thing on your mind. Your GPS device, smartphone, whatever, is still on the bike while you are somewhere else. Having a coffee, paying for fuel, visiting a shop, there are many reasons to walk away from the bike for a moment.
It is understandable that you don't lock the steering, switch on the alarm, attach the disc brake lock and use the cover. Not taking the GPS off the RAM mount is a lot less smart. And yet it happens. Charity is good, of course, but maybe handing out free GPS devices or smartphones is taking it a bit far.
This is a safety knob. Note that RAM does not call it an anti-theft knob.
You replace the standard knob on your RAM Mount with this typical 7-pin cover. As long as you don't have the matching 7-pin cap, the thread won't take. Then you can keep on spinning it until the rightful owner of the bike returns.
RAM also offers the caps separately, so dedicated thieves can still take off with your GPS device or smartphone. On the other hand, if someone takes off with the entire bike, they also have the mounted GPS device or smartphone. So there's no winning this, unless you use the locks and bring the devices with you. Anyway, the safety knob makes it a bit harder to get away with the GPS device or smartphone in an instant. Look at it as an extra threshold, an obstacle that slows down or discourages the occasional thief. And that's how it should be used.