Upper ceiling (for RC) 400ft, lower 350ft that leaves a fairly narrow band, oh BTW is that barometric, referenced to what?, how often updated? or GPS? what tolerance? 5%? where land falls off is it average over 50ft or something?
No wonder someone spotted it would be hard to police.
That bloke from NZ talk some good points
As for the privacy thing that's harder, could the drone operator over a certain size be required to have a bluetooth locator (like StickNFind or Tile) on board when in an urban setting? That way peoples smartphones with the app could create a realtime ground radar for drones. If you're out of town, or don't intend to fly over buildings or people no requirement to fit but should your untagged vehicle end up in some town garden you will need to justify it.