Which is done purely on speculative precaution and isn't based on any case law. In fact, the little case law that exists on the idea/expression distinction as r

Which is done purely on speculative precaution and isn't based on any case law. In fact, the little case law that exists on the idea/expression distinction as related to software copyrights ended up in favor of the direct source code/disassembly reading approach (Sony v. Connectix)