I wasn't admin of the freebuild server, but somehow this user was able to trick the SA into deleting all bricks instead of just theirs (they had a 15600 brick count and were lagging the server to hell).
I looked up the BLID on the forums, and sure enough there was another thread about this user under a different name.
As they left, they said this:
Seems like a troublemaker. We lost about 30 minutes of progress on the freebuild while about 15 people were online. In short, things were very much lost.