Hi,
I’m totally aware that ganking players is allowed on a PVP server, specially if 20+ levels separate the ganker from the ganki 
Having a nice wow experience is important. Unfortunately, some troublemaker players are subscribed to the game just to release their frustration of their real life…
I would like to suggest an internal debuff whenever a high-level player attacks a gray player, this debuff will simply reduce his damage to a % against the low player. % will scale with the difference of level, and can ramp up to 90% or more if a humongous difference exists.
It is a simple algorithm that blizzard how to elaborate, so guys, what do you think?
Of course, if any gankers roaming on this forum, it would be pleasant to hear from them.
regards