Earlier quoted context omitted.
Let me ask you this hypothetical question instead: What if we have a "brain encryption" technology that allows encrypting your brain so that brain scanners, thought detecting methods or emotion detectors cannot see through it? Would customs be allowed to ask for the decryption key? Or should the customs just ignore whatever is encrypted inside?
Of course they should be allowed to do so. That would eradicate drug trafficking and cross-border terrorism. I would say the benefit is too good, weighing against privacy.
Furthermore, if you want to stop drug trafficking, legalize them.