https://techcrunch.com/2019/09/02/denied-entry-united-states...
> But in identifying these technical differences, the court never explains why they justify a lower standard for manual searches.
Their observations precisely describe the situation the authors of the constitution would expect of every search (barring consideration of concepts foreign to them), when they included the fourth amendment. I would be very interested to hear the court's justification, though I suppose the absence of such speaks for itself.
Obviously, even absent technology, judges making these decisions and not even explaining major aspects of it would be unacceptable. But the technology gives complexity that they love to use as a shield, or as a sword against things they secretly don’t like.
But if you get caught, the consequences could be disastrous. For the person whose phone it is, you could get a lifetime ban from the US or charged with a felony. For the developer of a such a feature, the feds are very likely to come after them too (I think there's a strong 1st amendment case, but I wouldn't like to have to fight it in court!)
There's a lot of discussion about it you can search "deniability" on their GitHub issue tracker or socials.