I haven't noticed griefer activity for months now in the sims I am visiting frequently. It seems they come and go, and the more succesful a business is, the more griefers you can get. Whatever. I was visiting the region of Daikoku today, which is always quite populated because Blackheart's Cafe is in it and became the witness of a griefer attack.
Well, I've taken a look at the objects, filed an abuse report, but this is not going to help much, I guess, because the owner of the scripts was just created today and I bet there is soon going to be another avatar.
Well, here's also a picture of the whole event; click on it to get the bigger picture.
[Edit]: A funny thing is, when I take a look at the picture no: I've never realized until now that water is reflecting objects above it. Cool.
[2nd Edit] Seems those attacks were already happening last week, too, according to the Avastar #39.