2 things,
1) I think the community should get to know what people get banned for. I understand why we don't - because if the person doesn't know what was detected they could give in things that they weren't detected on - but after 'x' days the chance should be gone, and the community should be able to know what exactly the person used. Cheat/Mod is very vague, and could mean many different things.
2) If it's a cheat - than sure he should know it's his fault. If it's textures, than it's very subjective. I know for myself, I likely would be banned right now but you forum messaged me to change my email - then informed me that the textures I was using are no longer legal (sunmans). But, if you only did this through email, and did not forum message me, I would have never checked, and likely got banned. It hasn't been made 100% which textures are legal/notlegal, and it's a subjective matter - but your pack hasn't been finished completely yet to be able to say everyone MUST use it. I think it's only really clear to english-speaking regular forum users that your textures are really the only legal ones, and other ones (which can be downloaded from forums....) are NOT legal.
The fact that many people have downloaded sunman's textures from this forum probably made them assume it's legal. So they never questioned their textures. Why would something bannable be on the forum of the game?
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That being said, this is all speculation on it being a slight-texture issue, something that would not have been bannable a year ago. But, I could be completely mistaken.
Anyways, I personally think if you're going to have a committee, use them for what they can do - communicating with the community. When telling people "change your email" - "check your textures" etc... the committee can easily contact everyone they need. It would have taken the same effort as sending the email - Post in committee thread --> Contact name in regards to his textures --> Someone responds --> Done and proof of contact, if nothing changed then 100% bannable as theres proof he was informed. (THIS ONLY WORKS FOR TEXTURES). Obviously with a real cheat auto-ban is all that's needed.