Official bootloader unlocks [1] are different and this is exactly why. If the devices you care about have official unlocks, you're not personally affected by this DMCA exception (no matter what you want to do to your device software). If they don't, there's some DMCA-defined circumvention along the way to some things you might want to do and you should pay close attention to this particular rulemaking...

[1] Nexus devices, most Sony Ericsson phones, many HTC phones, soon to include the ASUS Transformer Prime, ...