Warlocks are not human? That is exactly why being branded a warlock is something to be feared by minor talents more so because some wardens can be very creative in explaining the laws when it suits them, see Morgan.
Who did not trust his own system, and he should know.
Who also showed that the white councils attitude to fair trials is not restricted to warlocks. Nobody accused Morgan of being a warlock but he was hooded anyway and had no defense exept for what nepotism brought him.
We know the warden counted members like Justin so expecting exemplary behaviour from all of them is not realistic. And more important thee is no appeal possible and the whole affair can be finished on site with whoever available.
So much power with so little oversight and no appeal or second opinion is scary. It is not good for people even the best of them.
And what Bob said was not a lie, with that cloack he can.
In non-magic human society, people go to jail. There are several aspects of this: Punishment, possible rehabilitation and to separate people, who break the law from people, who don't break the laws.
With black magic, there is the issue of black magic corrupting the mind and soul. Once a magic user does enough bad things, their minds are irreparable. That is the premise we have here. Molly rewired heads of how many people? 2? Note her impulse control issues. And she had very good intentions.
@Arjan: Your whole argument is basically "anarchy for everyone and people will naturally behave well" combined with "Death to the fascist oppressors!". This doesn't hold water in any society for long, Mr. Shoe. If a society is to have rules, there need be enforcers who make sure that the rules don't get broken. It's plain and simple like that. Why, do you ask? For the very same reason, why communism can't work efficiently and tends to break down eventually. Because of human nature. Most human are naturally selfish creatures, even though during our lives in some civilizations, we learn to behave a lot less selfishly. And yes, there are some people who for one reason or another are fairly little selfish or even not at all. But those are few and far between.
Now, to explain, why it's counterintuitive for wardens to abuse their power:
1) Even talented mages can be born from less talented mages. Therefore if mages wish to live on as a species, they actually need to protect the lesser talents ] ref.: White Night ]. So if one warden would feel like bullying/killing some lesser talents, another warden would feel compelled to stop him.
2) Truly strong people don't feel the need to bully the weak. It may sound like a cliché, but it's also the truth. Because weak people pose no challenge. Strong people became strong by overcoming real challenges. Same thing goes for smart people. And if said person feels pride in his achievements, bullying weak people tarnishes his own self-image.
3) It's one thing to keep people scared of wardens. It keeps them on their toes. Let's say, that a single warden went rogue and his targets don't manage to tell anyone for some reason [ you know, because there are no phones, no Internet, no mail, hell, not even a fire to send smoke signals. ]. I'd like to ask you a few questions, if you don't mind:
a) Why wouldn't the targets simply run away?
b) Holding a hostage is exhausting and you have to keep them alive, if you really, really want to earn your De Sade badge. How do you do this while actually performing your Warden duties?
... and finally...
c) Wardens are not immortal. They are not gods. They may be very powerful but that doesn't mean that they are unbeatable with any other means than magic. And while magic is nifty, I read somewhere, that it's very difficult to cast a spell when someone bashes you over the head or kicks you into a garbage can. So, pray, explain to me: how precisely would said rogue warden make sure that his victims wouldn't stick together, stand up to him and either knock him out or even kill him?