In your opinion, which rule violation is the worst?

[LittleImp]

I do not see how data mining is different from the people who clear all content day 1 of the patch dropping. It is not possible to see things that are not in the actual game at the time since there is no PTR here.

Datamining can be done before the servers even go live, and can be used to do things like extract tooltip and debuff text/icons, which can create an unfair advantage in worlds first races.