before becoming a role model, Mr. Robot himself was an inquisitive newbie trying to understand the intricacies of the t'system

I kinda want to leave red trust in response, but it doesn't feel right to (ab)use DT-powers to do so. On the other hand, I obviously don't trust someone who leaves me random red trust without any reference link.
So, I'll leave this question for the community: what to do? This question has been answered ("do nothing"), thanks!

Be the bigger man!
With great power comes great responsibility (source unknown). Especially when you're on DefaultTrust (or if you want to be on DefaultTrust in the future), you shouldn't (ab)use that power by leaving (negative) feedback when someone does something you don't like. Your Sent feedback is what others use to judge your judgement.
If someone on the internet is mean to you: boo fucking hoo! Use the Ignore button, and forget about them.