What do we need to know to counter illegal use of drones?

How we can detect a drone ?
(preferably as far as possible)

How we can clasify a drone?
(preferably as early as possible)

How we can track a drone?
(preferably as long as possible)

How we can detect the pilot?
(preferably with exact location)

Does it carries a payload and what is it?

How to countermeasure ?

Which countermeasure is the most appropriate?