As far as my understanding and knowledge goes, back in 2004~2005, Game Masters did have this power and problems arose from this power.
CipSoft and Tibia have changed a lot since then.
I recall vividly how it was, I was 17 at the time and really obssessed with it, I'd be online for most of my free time, I'd read and follow ever source of information there was, I'd hop around different game worlds to see if there were any differences and so on. I have personally bumped into a handful of GMs and CMs, I never did mention any of their possible powers or their wrongdoing, but it was a recurrent matter back then.