or, more realistically, underpaid unbothered border guard sucks your hard drives down bit by bit, then asks for the password or you get jailed. Its part of a bureaucratic process, so having hidden volumes is great because you can easily provide the password for the unhidden volume, they open it up, run their algorithms to check your files and boom, you're through customs without some poorly managed arm of bureaucracy having your sensitive research / IP waiting to be stolen in the next hack of your technologically inept government. Stuff like hidden volumes is great for situations where your otherwise decent habits would be kneecapped by poorly thought out bureaucratic nonsense.