1) Google Nexus phones do come with this as the default.
2) For many Android devices (kit from MOT excepted), the hacks are pretty trivial. I suspect the protections on HTC phones are more of a "Warranty void if removed" sticker than something to really bar you from gaining root.
2) For many Android devices (kit from MOT excepted), the hacks are pretty trivial. I suspect the protections on HTC phones are more of a "Warranty void if removed" sticker than something to really bar you from gaining root.