In the case of things like Hulu, it's an attempt to enforce their geographic boundaries (so that Europeans don't buy cheap EC2 instances to watch America-only l

In the case of things like Hulu, it's an attempt to enforce their geographic boundaries (so that Europeans don't buy cheap EC2 instances to watch America-only licensed content). I assume most of the others are trying to block scrapers that copy all their content and republish it.