Virtual world Second Life had to close its doors for a short time on Sunday after a worm attack called grey goo.
The self-replicating worm planted spinning gold rings around the virtual world, which is inhabited by more than a million users.
Players treated the attack with a mixture of mirth and anger.
"Can this game get any more unpredictable and exciting?" asked one user, Loretta Lurra on the official Second Life blog.
As users interacted with the rings they replicated, resulting in a slowdown on the servers used by Second Life's creators Linden Lab, in California.
Second Life has become one of the most talked about developments in cyberspace in recent years.