I'm not agressive by nature but the things i am imagining to do to the little shit would make me a psychopath
I wouldn't let it get under your skin honestly, these little shits are never worth the time or energy.
We should almost thank him as he helped demonstrate some gaping holes in how we do things around here. Now we know not to trust those we don't know or haven't earned it and not to hand out permissions so loosey goosey.
Also, allowing sub-Communities to grow independent of the Community at large means we are unfamiliar with the bulk of the people robbing our Server bandwidth.
Honestly, in retrospect I'm surprised we got away with it as long as we have.
I do hope there is something in the phrase "what goes around comes around" though.