Though unfortunately these days, much 'smoking' is done by the addition of a chemical additive with a 'smoked' taste.(Cheap kippers and 'smoked' processed cheeses)
True: they don't actually smoke it these days; just add the smoky flavouring, unfortunately. I think there are some very small fish farms, etc, who have reverted to traditional ways of smoking, but their stuff costs an arm and a leg, so unless you've got loads of spare cash around with nothing else to spend it on ...