Sadly literally any DT member/s can tag the account if the accuser has convincing evidence towards the accused. And I don't think someone can be dragged down in something they haven't not done because the accuser needs sufficient and convincing evidence before even any member believe on what they are saying. And if someone gets tagged wrongly they will have the chance to defend themselves and getting the red tag off is possible as even though trust is not moderated DT members are fair to the system.
DT is a completely different subject to the OP of this thread. The trust system is indeed unmoderated and most people are unaware that they can customise their own trust network. Use the ~ character in front of any DT member whose judgement you disagree with and you will not see their ratings by default anymore.
That has no bearing on whether or not the Scam Accusations board should be censored.
