@AdinX
It is certainly an interesting question, but to my understanding you can't really do that. If I interpreted the license agreement right(aka. the long boring thing nobody ever reads), all derivative works belong to Blockland LLC. In this case, builds made in this program count as derivative work. Badspot, as a representative of Blockland LLC, expressed he doesn't care how people are using builds in this game, in fact he encourages saving. There are many posts where he clearly stated how he thinks "build stealing" is a non-issue.
Even if my interpretation is incorrect, you still could not sue. What would you claim? Damages? You need to prove losses have occurred because of the infringement of your copyright. Could you prove any monetary loss in this case? Moral damages? Perhaps, but it would be rather frivolous and I'm pretty sure the court would throw it out immediately.
Sorry for going off-topic.