You may have seen reference to the GHOST exploit that was recently announced.  You also may have seen some random reboots of our servers, taking you out of commission for 10 minutes or so.  We're patching all of our systems against this exploit (Just about done now) - this is  a fairly serious one that allows arbitrary script execution on servers, and is not really all that hard to do comparatively.  And unfortunately since it's a glibc issue, we really need to reboot all of the servers to completely protect.  So -- if you've seen your server reboot, or if you see that happening in the next day or so, this is why.  Just trying to protect you.