When it comes down to it, what's ethical or fair is relative to each person. Because religion and culture are such strong influences in the decisions people make, there isn't always a clear right or wrong choice. A method of hunting that one person finds unfair might be perfectly just to someone who has different beliefs.
The biggest argument in favor of the "unfair" hunting methods is safety. Proponents believe that canned hunts can reduce accidents because hunters are aware of each other's positions. Public hunters have no way of knowing if another sportsman is hidden in the nearby brush. Safety is also a piece of the defense for Internet hunting.
Because no humans are operating guns by hand or present in the shooting area, Internet hunting basically ensures no accidents. But the main argument in favor of Internet hunting has to do with the rights of the disabled. We as a society strive daily to make the world as equal as possible for every human, and Internet hunting brings a new pastime to the disabled who would otherwise probably never be able to hunt [source: Grass Roots]. While animal protection movements don't always agree with this argument, they do recognize it as a consideration.
Overall, there is not an abundance of information specifically defending these methods, but there are arguments that defend the individual rights of citizens. For example, some supporters of controversial hunting methods feel that private property owners should be able to use their land as they choose.
At this point, there exists no cut and dry answer to the debate surrounding unfair hunting practices, but if you feel strongly one way or the other research ways to do your part. Both sides of the topic have outlets for your participation.