Hmm... well, if I were to venture a guess, I'd say that people have reverse-engineered usable codes, down to the bare essentials. The solid, recognizable words would the base for the code's information - a blank slate, except perhaps for some categorization. Upon this is added the specific information, which then alters the characters. I'd guess that the numerous "base patterns" would help to deter the reverse engineering (you may have two or three codes that look similar, then another that's completely different,) but apparently that didn't fully work.
Does that make sense at all?
Go Moon!