Chainfire posted that he is hearing from good sources that KNOX is indeed an Efuse. I have not heard the word efuse since the Droid X days. If this turns out to be the case when you touch the bootloader you will trip the efuse which will void the warranty. Even worse service center instructions are to refuse any repairs on devices that have the efuse tripped status. The reason being that the phone was damaged by the owner. So this sucks in so many ways. If the speaker goes bad they refuse to repair it because you tripped the efuse which has absolutely nothing to do with the way the speaker works.
There is an EU regulation that can be interpreted to say rooting and unlocking can't void a warranty, but you may have to take the shop to court which may get you know where. Does any of this make you weary when it comes to rooting your phone. As for me who cares I change phones often enough that I don't personally have to worry with manufactures warranties. I can see where if you hold on to a phone for more than a year this could possibly be a big issue. Will this keep you from purchasing Samsung phones?
Via ChainFire+