I encountered this thread on Groundspeak's forums yesterday:http://forums.groundspeak.com/GC/index.php?showtopic=342877&st=0
Like most threads, there is a bit of wading through the much to get to the prize (any useful civil discussion).
The concept, of either using a drone to hide a cache, or requiring a drone as a special tool to retrieve one (or at least the coordinates to the next stage in a multi...) intrigues me. But what really struck me when I encountered this thread was the question it immediately brought to mind: When had that been banned?
As and end user of Groundspeak's services, you'd never know. The first hint comes in post 2o of that thread, in which a moderator makes this reference: "Geocaching HQ asked all Community Volunteer Reviewers in 2015 to not publish caches involving the use of drones."
CAUTION RANT STARTS HERE
Why is it that Groundspeak can't promulgate changes publicly, and post those changes to the caching guidelines (where you will currently find nor reference to drones). Why do they find it necessary to burden the volunteer reviewers with being the enforcers of rules that the end users cannot know exist? This impositions both the reviewer making him/her look like the bad guy, and the end user who wastes time creating something that cannot be approved.
END OF RANT
There's lots of good reasons that Unmanned Air Systems (UAS) as well as other unmanned systems (these now exist for all modes of transport) might not be a good mix with geocaching. There are also lots of good arguments for allowing them as well as other innovations to what should be an evolving game. Post #59 in the linked thread captures some of that well.
At any rate, an interesting topic for discussion, and one local Psycho Urban cache is referred to in the thread. Another cache has apparently been grandfathered, as it was published before the secret ban, if you've got a drone and an interest in going after it (be forewarned it is in Illinois, but what cacher isn't up for a road trip?!?), check it out here:https://coord.info/GC5AA1H