Maybe if people are using it to pull really big groups really fast.
The
tools using community has been doing things like aggroing very large groups of mobs, pos hacking away, then abusing the game's Z-axis mob positional reset by changing the player's Z-axis location up/down to get all aggroed mobs to instantly teleport to their location.
This is to make grouping up mobs for AOEing faster. How many mobs you have aggroed == how many positional updates the game has to send, all at once, for every player abusing this mechanic.
It is not outside the realm of possibility that abuse of POS hacking in this way has a very large effect on server performance. Bigger server -> more players doing this -> more load.
Z-axis changing doesn't even get picked up as a POS hack by any existing automated detection, so is seen as "safe".