Trust systems are always hard or impossible to do right. The default trust list system here makes things tough. At the very least, I think it would need some changes to how things are calculated and shown to people by default.
Currently, it's widely known that people are scared to say anything negative to people in the default trust list. It should never be like this. Some DT/DT2 members are redrate/negativetrust -happy, and can be said to abuse the position they have. This also shouldn't be like that. This affects majority of users: almost everyone is using default trust settings, meaning people trust DefaultTrust with the depth of 2.
Getting negative trust (and/or rating) from a DT1/DT2 member easily ruins account, or at the very least damages the general view of it. People generally treat others with red trust as untrustworthy, even though that may only be the result of some petty outburst by someone in the DT list. This happened to me, so I'm now being vocal about it. I used to have +48 green trust, now I have -1 orange trust. My business here has taken a hit due to this, especially when dealing with newer users.
What happened?
Shortly, I pissed off DT2 member called Vod. He was rude against me, called me a scammer and so on, so I red-rated him as I don't trust people who call me a scammer. Later he contacted me about it and told me that he doesn't see me as untrustworthy. But, he threatened to red-rate me unless I changed my rating. I didn't obey, so he red-rated me. So I told him that I don't trust him and I guess he took it very personally leading to this shit storm. Remember, most people are afraid to tell these people negative things about them. In this whole chain of events, which was forced to be public, Vod made illogical and contradictory statements to justify wrecking my account. He also blatantly and provably lies in his reasoning in his rating towards me, and in his public comments about this. But what can I or anyone really do about it? People are afraid to call him out. And people don't want to get into a shit storm.
More info about this in thread
https://bitcointalk.org/index.php?topic=3869593.0 and message
https://bitcointalk.org/index.php?topic=3869593.msg38658847#msg38658847 with a try of a summary of the events.
I know I am of course not the only one being abused like this. There are plenty of examples. I am escalating this further, because this appears to me as clear abuse and I think I could do (or get people to do) something about it. Of course anyone technically can rate anyone how they like, even based on complete bullshit, but community/someone who can should act on it. Even when the abuser has done good deeds most of the times, like Vod.
All in all, I think these sort of things have considerably negative impact on the forum. Community, be it staff or regular users, should act on it. I know it's a messy job.
https://bitcointalk.org/index.php?topic=4415201.msg39447493#msg39447493Edit (Aug 1):
Changed topic from Trust system abuse to Trust system abuse / DT2 member Vod is provably dishonestly rating people