Is Anet doing anything about griefing?
Nothing yet. It was quite a sight last week when one troll built 4000 supply worth of ballistas over the course of 5 hours. I have the screenshots, and oddly, I got a network error trying to invite or communicate with him, so I’ve got a weird feeling it was a bot.
Document it and submit a support ticket under “violations”. It works, if you present them with enough facts over a period of time. Usually takes them about two weeks to do their due diligence and not falsely ban someone. But you have to pretty much submit irrefutable proof.
That includes:
Multiple screenshots
Fraps (link for it)
Date/time where it happened
Where/what map/which server
Griefers account name and toon they were playing while doing it
Your account and toon you were on when you witnessed it.
If it only happens once, they won’t do anything. Repeated griefing is key, over a period of time.