Caustic Ramblings

That's a very solid point, but I would add that a group can have "organization" without being a legally-recognized entity. Just look at the mafia! Less extreme, but my mom used to play Bunco with the ladies in our neighborhood. They rotated who had responsibility for what (who hosted, who bought drinks, who handled the pot, and so forth), and there were some rules around that, but it was never a legal entity or something that advertised itself. So there're grades of "organization," and some might be more helpful for different purposes or under different circumstances than others.