What do you get when you have virtual worlds with scriptable objects? Cracker attacks, of course. In this case, a user in Second Life built objects that, via script, produce further objects. This is a classic attack scenario in such worlds - overloading servers through high load, i.e., a classic DOS from within. What was interesting about this attack was that these objects catapulted every avatar a few million meters into the air - possibly to hinder cleanup efforts.
Cleanup efforts? Yes. The system of Second Life is a virtual world with many scripted objects - so you can't just throw everything away, as this would destroy the users' content. Instead, all regions (in principle, a region is a server in a large server farm) that were attacked had to be cleaned of exactly the affected objects. To do this, the Lindens (the employees of the operator) first approached these objects inworld (i.e., within the simulation environment) to examine them. Presumably, the operator will have tools for mass cleanup of malicious objects, but nevertheless, the entire work took several hours!
Well, one might say that this is trivial - after all, it's just a virtual world on a server cluster, nothing more. But Second Life is more - among other things, it is a micropayment system. And a lot of money is transacted there - thousands of US dollars per hour (and not just to the operator, but also among the users themselves!). There is therefore direct economic damage from the downtime. Not to mention the interactions of users in the system and events taking place - for example, on that evening, there were two major openings of new clubs with live music. The musicians were completely disconnected from the system by the events, as they no longer received any feedback, they did not know whether they were still live or not (although the streams usually continued to run) and of course, a lot of people's party was ruined. And the club owners certainly had a different idea of their opening party.
All in all, of course, predictable - because any system with influence possibilities will be misused by people, even if it is out of sheer malice - but nevertheless extremely annoying.