US govt drafts Google, Walmart, Amazon, BestBuy execs for drone registration system

Re: I'll bet that ....

A license plate as sole ID is unlikely simply because many drones don't have the panel space needed to display an N number with even 25mm (1") high letters and on top of that it would be unreadable from any useful distance. That said, having the reg. written on the side of every drone is still useful as passive, on-ground ID if you're looking for a lost drone or if a cop thinks you've been a naughty boy.

I'd guess the more likely solution would be some form of low powered transponder or simply a device that broadcasts the reg. every 5 secs or so. Either should be cheap enough to mass produce because it only needs a range of at most 2-3 km (1-2 miles). Using one of the longer range IOT radio link modules would hold costs, weight and weight power use down. As a sweetener, it could double as a finder for downed or crashed drones.