Supposed to help with connectivity issues.
Some content on your device may also be invalidated and cannot be accessed any more because of invalid DRM security keys. This includes content that you may have purchased through a 3rd party vendor and through HTC. Furthermore, although you will still be able to receive updates to your device via FOTA (“firmware over the air”), we do not guarantee that updating your device via FOTA will not render your device unusable. Please understand that you will not be able to return your device to the original state and going forward your device may not be held covered under the warranty for all claims resulting from the unlocking of the bootloader. HTC bears no responsibility if your device is no longer usable afterwards.