I think marking will help, but obviously it's going to depend largely on the size of the drone and the size of the marking on it.
I don't know whether, for example, Transport Canada or others are working on technology to use triangulation to find the controller. That is, in fact, one of the challenges with UAVs generally. If you see something flying up there, you don't necessarily know where the person is who's controlling it. I think that is going to be one of the regulatory challenges.
However, registration and marking would take us a significant step forward compared with where we are now.