Kill Your Friends! (Patreon)

This exploit first requires you to obtain the item N'yleth Sliver Of N'zoth  https://www.wowhead.com/item=175246/nlyeth-sliver-of-nzoth 

This item allows you to become temporarily hostile to your own faction and kill same-faction players. 

To obtain this item is normally quite difficult as it involves lots of world pvp, however this exploit makes it very easy to get:

 https://www.patreon.com/posts/28117135 

(this exploit allows you to control a water elemental with raid boss level players and kill anything in Nazjatar)

I find it enormous fun to kill random unsuspecting players of my own faction with N'yleth, or use the Net-o-matic 5000 on airborne players, and especially to use knockback on characters in Boralus harbor to send them flying into the sea. 

N'yleth has a long cooldown so to do it repeatedly you will need to use alts and/or class trials as the cooldown is not shared across characters, but, as a toy, can be used by all of them.  The problem with this strategy is that the guards and other players tend to kill you, but fortunately there's a solution, the following macro: 

 /cancelaura servant of n'zoth 

 allows you to return to friendly status instantly, meaning you can attack players without any comeback!

You can do the same thing by removing the buff manually but the small amount of extra time this requires will usually result in you being dead before you manage to do it unless your character has main-level gear.

Note for newer patreons: I spend 99% of my time looking for things which are actually useful, I just like to post dumb shit like this every now and again to break things up, and also to waste Blizzard's time.