Why, exactly, do you care about free kills in the DA? 
The simple answer is because System Victory messages are directly transferable for 'wtg' messages from other players, which is in turn transferable to bolstering ones ego.
Perhaps a couple ground rules (that are ENFORCED) would help, such as 'stay respectable' and 'don't interrupt duels'. As it is, there is nothing saying that people can't interrupt a duel, or shouldn't be a total d'bag.
/shrug/
It's seemingly just a tumor to 'Aces High' as I see it now.
Unfortunately EskimoJoe there really is no way to enforce ethics. Furthermore players have different goals and values. As a counterpoint to your opinion there is a certain honesty to the Furball lake in the 'law of the jungle' fashion and this has its own merit.
Before another 'remove the Furball lake' campaign gains momentum, again I must state there is a small core of AH pilots who enjoy flying there and not everyone is like the griefer that you and Pervert seem to be citing. It sounds to me like you've been made the temporary squeaky toy of a genuine Furbal lake pest, who changes his callsign routinely and uses a second account to dot wingman you and then systematically ruin your flying session by attacking you in a Tempest.
It is unfair to those regular players to make a significant change without consulting them. I suggest in general if you don't go there then don't comment and if you do then expend a little energy trying to understand the nature of the place and see if you can exploit that for your own enjoyment or edification. There are good players in there, don't let a single turd ruin the pool for you.
Additionally there used to be an Arena Message prohibiting the disruption of private duels which had since been removed. There was a thread campaigning for its reinstatement but to no avail.
Edit: What exactly is the correct spelling of 'Furball'?
