The idea has all kinds of stupid all over it. IF you want to put some kind of tracking item inside your [expensive] firearm, that's your right. But to make something like that mandatory is beyond moronic. Never mind the logistical issues with having a ruggedized GPS that can handle the G/shock forces involved. How about making one small enough to even fit pistols? Or are they thinking of making magazine base plates hold the tech? Or do they expect them to be integrated into the grips on pistols? Of course WE know that they'll want people to fit their existing guns with these devices. Rifles could be easier to fit, since they often (but not always) have room in the stock for such an item. Even then, it could require changing of a stock. What happens when that either depreciates the value, or the destroys the ergonomics of the rifle? Then there's changing the batteries in for the GPS items.
Of course, there's also the sinister side of this (as I'm sure MANY here are already seeing) of someone being able to locate ALL GPS equipped firearms. Making seizure much easier.
IMO this idea is right up there with 'smart' guns... Something that's a libtard's/dumbocrat's wet dream. Never mind how it's something that either won't work, or will be used to erode OUR rights. Of course, they'll want to use this as a 'compromise' item for more gun CONTROL. They can already have a colossal "f*** YOU" from me.