[Zak]

This probably doesn't hold up legally, but it does hold up logically: if the reason a border search exemption exists is to prevent importation of material that is unlawful to import, wiping a storage device also fulfills that purpose.

[RegW]

It would seem that the officer was searching for evidence of a crime, not to prevent importation.

However, did that evidence really exist? And if it did, was it for something else? Perhaps, the guy just worried about something far more mundane being discovered? We shall never know.

Think Schrodinger's password.

[Zak]

The border search exemption is not intended to allow searching for evidence of crimes that aren't related to importing something illegally. Of course CPB isn't expected to ignore evidence of other crimes they happen to see incidentally while checking for things that are illegal to import.

Courts have been fairly tolerant of law enforcement using pretexts like that to expand their powers.

[danudey]

This is the issue with these sorts of laws. How do you make it illegal to destroy evidence of criminal misconduct when the destruction of evidence can make it impossible to prove it ever existed?

That seems to be along the lines of what they're arguing here - they wanted to perform an ostensibly legal search, and he destroyed everything that might have been evidence either way. It would be like a corporation getting an e-mail from the SEC saying "Give us all the communications your company has had about these three stocks" and the company saying "Oops someone erased our e-mail server so I guess we don't have any communications about that."

If you're this paranoid about being searched, or you have something to hide (even if that 'something' is a sense of morality and a desire for a free and just society), wipe your phone before you cross the border and not during. Put some basic apps on (reddit, twitter, etc), leave them logged out or put them on some empty account and tell them you're not a big social media guy or you're on a digital cleanse or something. Wiping your phone when you're being detained by law enforcement is a bad look one way or the other.

[Zak]

A "bad look" is legally irrelevant. A US citizen has an almost unlimited right to enter the USA carrying anything that's legal to import. Blank phones are legal to import.