A large majority of the drones being used are manufactured by DJI, they aren’t home built. You can pick one up from any major electrical retailer starting at about $500. The user can unlock the legal limitations, particularly the 400ft ceiling, also nothing to stop one flying a drone at night or close to a major airport particularly with on older version of firmware.
I live close to Darwin Airport and I’ve seen idiots flying drones around the area and even at night. In their defence, most people just don’t know or understand the rules. The retailers don’t give a toss, they just want to get the things through the checkout.