How "ROM Mark", Blu-ray protection system, works

 
CDRinfo dug through recent patent filings to find information on how at least one of the levels of content protection on the Blu-ray format will work.

Besides just being encrypted via AACS, each disc pressed will have a mark unique to the machine that made it.  Customs agents will be able to verify authenticity using a specially modified player that checks the code on the disc to compare where the mark should be and where it is. The developers claim pirates would have to reverse engineer the entire system to defeat it, at great time and expense. Of course, if there's anything previous attempts at content protection have taught us, it's that pirates have all the time, money and skill necessary, so we'll see what happens.

My only question is if this will at all effect people making copies for personal use. It doesn't appear that it would, since you don't particularly need to hide the fact that it's a copy from yourself, and customs agents probably won't need a specially modified player to find out what you've been downloading from newsgroups to your "L33T backupz" collection.