Quite. They normally delete it, though, if you ask nicely.
There was this one child who did this, and placed the brick right in the middle of nowhere and started spawning bots. So I asked him "Could you please removed that? The host doesn't like spam". So he deleted it, only then to place another one on a red 16x16 baseplate.
Needless to say, I laughed hysterically and asked him to delete it before he left. :P