I agree - it is how it is used that is benificial or not - not that there is black or white majick or good vs the dark arts. It is the choices people make as they utilize it. If the intention is to harm - there you go. Like in Wiccan, "harm none" is the first tenant.
And really, all peoples of all faiths have had power - and wielded power - and at times used their power for bad purposes. ALL RELIGIONS. Often in the name of their gods or God.