Trusted harder to get

It has come to my attention that we were griefed a while back, and recently (by the luck of an individuals idiocy) stopped a grief team on weathercraft! I think it would be safer to prove that you can be trusted some other way than just finding a code.
The downside is that I have no suggestions of how to make "trust" harder to get. Please note this is just an idea that could save the server in the near future from griefers such as the ones before, but does not have to be put into action,

Many thanks for reading,

~Sheep

The rank "Trusted" is missleading as you arent really trusted that is why we have trustedville, to prove that you are 100% trusworthy (this is why you are aloud to build in the rest of the world when you are promoted). Also the griefs do not matter as we have hawkeye.
EDIT: Shouldn't this be in the suggested forum?

Avo's right, this belongs in the suggestions/feedback section of the forums.

Basically, if you have ever been on any other server with the rank guest, they usually do something so simple, but useful to the server to get the next rank up, in our case 'trusted'. I suggest, rather than making it hard, they can post their IGN on the minecraft forum thread, thus bumping the thread, bringing in more play traffic. They way we have it, guests can tp so they can access trusted rank in a matter of seconds, as they will probably not read the signs, there was a suggestion ingame a few days ago about a quiz for the rules and info, this wouldn't be such a bad idea and it could become an addition to the Builder rank requirements.

TD;DR: