Depends entirely on someones definition of ganking. Personally, i think ganking is any form of pvp where one player initiates while having a strong advantage - 2v1, other player is in combat with a mob, other players has low hp, other player is lower level, ganker is on a twink and geared through the teeth
By using that definition, all world pvp is ganking. I have always maintained that the absolute only gameplay reason for rolling on a pvp realm Vs pve realm is to allow you to engage another player in pvp when they would normally not have wanted that. Now, there might be other social reasons, like your friends already rolling on that realm, or a guild you want to join, so there is always exceptions to every rule, but for the average player, that is their motivation.
That is why i have always found it amusing when someone cries about being ganked or camped - when the only reason to roll on a pvp server is to gank.......someones gotta be on the receiving end of that.
I remember many occasion in STV, but one in particular where an alliance character 10 lvls too high to be there started complaining he was being camped by a lvl 60. Long story short, there was a fight between two lvl 30 somethings over one of the quest mobs, the horde won and got the tag and kill. Alliance player logged to his "main" which was high 40s or similar, and went back and ganked the horde. Horde swapped to his 60 and camped the guy for 15 minutes until he started crying. We only found this out because of a friend with 2 accounts who asked the player straight up.
I have great and terrible memories of the arms race that would begin when someone got ganked.