Well I don't really have an opinion on leaving those companies negative feedback because I know nothing of the circumstances, but what I want to know is, Mabsark, do you feel leaving retaliatory negative feedback to der_troll is appropriate considering yours carries so much more weight?
At the time is was left they carried equal weight and I reached out to der_troll immediately via PM urging him to reread the thread and reconsider his decision. Until he responds to me, then yes, I do think it's appropriate.
Would it be appropriate for me to change that feedback just because der_troll's trust level changed though?
Well since it was unwarranted in the first place to retaliate with negative feedback I think it's fair to change it to a neutral rating or remove it. Just because someone else abuses the trust system doesn't mean you should too, that's one of the points of being on default trust and having a higher feedback weight, to not misuse it and use it to point out scams and scammers. If you want to keep your default trust position I suggest you remove it and rethink the ones you've left if they would hold up when a person makes a thread like this, whether it's proof or your train of thought that led up to your decision.