A bored Newbie with a hacked Legendary account could pull this off. Then exclude all other DT1 accounts, and the hostile takeover of the trust network is complete (until manual intervention).

I can imagine other communities will make their own DT1 "clique": for example a group of Russians, a group of Indonesians and a group of bounty hunters. As long as they stay out of each other's hair, they can co-exist. The moment they touch, it feels like a black hole collision competing for exclusions.
The old DT-system felt like it meant something, the new system changes every few hours.

Figured I might as well get this shit public as I am gonna have half the red army after me, I don't care if they manage to exclude me from DT, I just figure others need to be made aware of this behavior

~ But if it looks like a "scammer's cartel" is forming, then I'd change the criteria to fix it. For example, one obvious weak point is that you can try to push an infinite number of people into DT1 by trusting as many people as you want; one way to try to fix this would be to take only a fixed-size random subset of everyone's trust list into account, perhaps with the size determined by the truster's merit. But for now I am very much inclined to just let it roll for a while and see exactly where the cracks appear.