That's the thing that needs to be managed: a strong, vindictive show of force to prove to petty thieves like these that it's not worth ruining their game over. It should be a grudge that shouldn't be easily let go otherwise it just encourages them to do the same to other factions. Make sure to message factions that he joins in about this forum; tell them how much of an untrustworthy little poptart this shithead is.
Make it so that they can't play the game and make them quit the game forever. Help them learn the value of "FAFO" this kind of approach helps make all kinds of communities like torn a better place. less fucktards like him.
The difference being "morals" also says a lot about the person and how they conduct themselves outside of the game.
If they're willing to be a piece of shit "in-game," then it really says a lot about their personality and their attitude outside of the game.
if we can't keep up the hate or grudge then that just means you aint hating enough lmfao, twitter does this shit for free, torn already gave us tools to really make them feel it