CSS is the encryption scheme used for region-coding DVDs, so you can't play them on an unrestricted player (such as freeware meant for Linux). deCSS was a program (really just a few hundred lines of code, actually) that circumvented this. Under the DMCA (Digital Millenium Copyright Act) the mere publication of that code is a crime...so of course, it spread everywhere.what exactly is DeCSS and MPAA?