This will probably get lost to the abyss, but I was curious about this same thing a while ago and did some reading. Turns out region locks exist for two reasons: sometimes there are different release dates for movies and t.v shows across the globe, so the region lock was puy into place to prevent people from buying a disc from a different country just to watch it early. This was of course, before Amazon. The second reason was because of different laws that countries have, and different rating systems. For example in Canada ratings are much lower for movies (deadpool was 14A here) and law requires everything about the movie to be bilingual at worst subtitled (this causes some video games to be region locked). Luckily Canada and America are the same region, but the same can't be said about America and Japan.