Since drones are not "arms" , ownership is not covered in the Bill of rights , amendments, or articles in the constitution, they are not above the reach of the law.
So, requiring drone pilots to be licensed should be doable.
I have several drone services that I use for LIDAR surveys in sinkhole and lineaments/faults areas, all my drone pilot contractors are state licensed as a requirement from my insurance carrier, with me as additional insured. (Drone flying is a licensed "priviledge" , not a right)
We use the bigass octacopters which can hurt ya if their props hit you, awire, a rare bird.
Payloads arent real high but theyre getting better with newer more powerful batteries linked up in parallel so you can almost fly to the coast with one.
My one drone contractor (most of these guys are like big kids havin fun and gettin payed) drove his octacopter into a barn just like he was aiming for it. Sucker just broke into a gazillion pieces and we lost two weeks time till he could rig up another with the LIDAR unit (after he got it repaired). He had to file a safty incidence report, and was given points
Pa requires contractor who use drones to have a licensed pilot ,Im not sure about hobbyists with these little peeps that you can buy at a TARGET store or Wally Mart. Most of the ones with cameras or the Go Pros have a GPS hookup nd can be trcked pretty easily.