It's probably to stop people from importing cheaper devices from other regions. Samsung wants the flexibility to price devices differently by region/market and that doesn't work if the consumer can import the cheapest one instead. This will probably continue to escalate because the way the market is heading prices have to get lower in expanding/poorer markets while customers in established/wealthier markets are willing to pay more. This is a side effect of trying to win the race to the bottom on price.