Ask HN: Isn't forced breach of privacy counter intuitive?

The other day I read that soon you will have to give your social media accounts password when you apply for a US visa and now I saw about a US-born NASA scientist being detained at the border until he unlocked his phone.

Am I the only one that sees how counter-intuitive the whole thing is? If a terrorist wants to come in the US, he will just make another facebook account or keep the secrets in another phone or in the cloud with no link to the device. There are options to conceal. What are these people thinking? Are they soo dumb? Or is there some big picture that I am not seeing?