Through reverse-engineering PlayStation 2 software, I have encountered a few grey areas (to me anyway) that I don't know how to deal with. In late 2011, SCE took legal action against the FMCB developer, on the grounds that some of the MECHACON cipher keys in the PS3MCA package violated their copyright. Although my questions are directly related to PlayStation 2 reverse-engineering and the console may be overlooked by SONY, I'm curious to know the rightful answers. So if having a few tables of numbers can be deemed an infringement of copyright, is that why some clone manufacturers omit the branding on their compatible parts (i.e. 3rd party replacement faceplate for my PSP has no "SONY" branding on it)? In our PS2 APA driver module, the partition magic string ("Sony Computer Entertainment Inc") was originally hidden by getting XOR'ed against the 'X' character. Could fear of violating the SONY copyright be a reason as to why they did that? Even if the string is neither used as a copyright message nor displayed? This string is probably a lot smaller than the cipher tables that they claimed and is plaintext. What about passwords? Officially, the system partitions on the PS2 HDD are password-locked. The passwords were stored in the HDD Utility Disc's packages, within the setup scripts. Personally, I believe the password system was to just prevent unauthorized access by 3rd party developers and/or users because the password does not actually encrypt/protect the contents. Since the passwords do not involve involve their DRM in any way, so would they still be illegal to disclose? Finally, if I do have some hardware register bit definitions, particularly those that may unlikely be interpreted purely without leaked documentation, would it be illegal to post re-interpretations of these register definitions on the Internet? Even if the definitions only share the same semantics, but aren't a 1:1 copy of the original? Thanks in advance!