This would actually be a plausible excuse for region locking. If the MPEG stream were somehow optimized for NTSC/PAL. If course the most likely reason is corpo

This would actually be a plausible excuse for region locking. If the MPEG stream were somehow optimized for NTSC/PAL. If course the most likely reason is corporate greed, but it's also fun to consider other possibilities. Another hypothetical reason would be for sales in Islamic nations where certain content is prohibited. They could show the government censors that there is some level enforcement to prevent "illegal media" from being easily watched. Whereas without it, the government could have potentially made DVDs illegal in their entire nation. I'm trying to see this through the lens of the design committee back in the early 90s.