alt Hacker NewsWhich, in my view, significantly decreases the value proposition, as there is no way to deactivate this feature to my knowledge (at least not without also opting out of other useful features under the "Handoff" umbrella).
A typical Apple feature, dreamed up by engineers that are presumably not aware of the existence of metered data plans...
You can disable it, actually.
Settings > General > AirDrop > turn off Use Cellular Data
That said, I don’t really see why you would disable that. It’s only a backup method for when the peer-to-peer connection fails. Unless you are sending huge files on a regular basis, I wouldn’t expect it to be worth disabling. Also, most metered plans I’ve encountered just cause your connection to be very slow after you hit the data cap.
If you are on a plan that automatically charges you excessive overage fees without warning and there is no other choice, then my condolences.