A "griefer" — person who disrupts video-games — is attacking the online world Second Life with self-replicating "grey goo" that is melting down the Second Life servers. "Grey goo" is shorthand for an apocalyptic nano-gone-wrong scenario wherein nanoassemblers replicate so profligately that they reduce the world to slurry.
4:55pm PST: There was a slight delay to our rolling restart while we continued our investigation. The rolling restart should begin soon, if you are currently in-world you will get a warning before your region is restarted – allowing you to teleport to another region. We hope to have logins open again very soon. Thanks again for everyone's patience during this issue.
4:35pm PST: As part of our effort to counter the recent grey goo attacks, we're currently doing a rolling restart of the grid to help clean it out, this means each region will be restarted over the course of the next few hours. Thanks again for your patience.
4:15pm PST: We are still in the process of investigating the grid-wide griefing attacks, as such we have momentarily disabled scripts and "money transfers to objects" as well on the entire grid. We apologize for this and thank for your patience. As soon as I have more information, I will pass it along.