My suggestion stems from the assumption that the person was interested enough in LEGO to buy big buildings in the first place. “Occam’s razor is a problem-solving principle … states that among competing hypotheses, the one with the fewest assumptions should be selected.” – wikipedia Of course, maybe he stole the modulars and needs other people to sell them for him so he doesn’t get caught. In which case, he is not a good candidate for the LUG.